US2555867A

US2555867A - Air launched radio station

Info

Publication number: US2555867A
Application number: US613151A
Authority: US
Inventors: Robert P Bennett
Original assignee: Individual
Current assignee: Individual
Priority date: 1945-08-28
Filing date: 1945-08-28
Publication date: 1951-06-05
Anticipated expiration: 1968-06-05

Description

June 5, 1951 v BENNETT 2,555,867

AIR LAUNCHED RADIO STATION (7 Filed Aug. 28, 1945 3 Sheets-Sheet 1 3 wu mm R BENNETT FIG, ROMBE T P R. P. BENNETT AIR LAUNCHED RADIO STATION June 5, 1951 3 Sheets-Sheet 2 Filed Apg. 28, 1945 O. 1 mo. mo. 7 1.1 Om

%% OMWVAM June 5, 195] R. P. BENNETT 2,555,867

AIR LAUNCHED RADIO STATION.

Filed Aug. 28, 1945 3 Sheets-Sheet 5 Igll/IIIIIIA VIIIIIII/I/I/l RQBERT BENNETT Patented June 5, 1951 UNITED STATES PATENT OFFICE AIR LAUNCHED RADIO STATION Robert P. Bennett, White Hall, Md., assignor, by mesne assignments, to the United States of America Application August 28, 1945, Serial No. 613,151

\ .mote or hostile territory.

In general, my invention resides in improvements of the air-launched radio station disclosed I and claimed in copending application Ser. #600,- 621, filed June 20, 1945, by Percival D. Lowell et a1.

' More particularly, the erection of the station to suitable operating position subsequent to its fall to earth is made more certain by one, or the other, preferably both of the following: mounting of the heavier components as close as possible to the nose of the station housing to provide low center of gravity and use of stationerecting legs which have great rotational in- 'ertia.

Also in accordance with my invention, the periods of transmission of the station are predetermined, as by a clock-controlled master switch, to facilitate reception from a number of such stations without mutual interference.

Further in accordance with my invention, interrlocli switches are utilized to ensure release of 1"" a the parachute and actuation of the erecting legs in proper sequence.

In accordance with another aspect of my invention, the mounting for the telescopic antenna of the station enables axial extension of the an- 'tenna upon deformation of the nose portion of the station housing.

My invention also resides in features of construction,.combination and arrangement herein described or disclosed.

Referring to the drawings:

Figure 1 is a general sectional view showing the construction of the housing and the location of theffmajor components.

Figure 2 is a circuit diagram of the apparatus mounted within the housing shown in Figure 1 and shows circuit connections between the timing device, the relaxation oscillator, and the radio transmitter.

Figure 3 is a sectional view taken on section 3-3 of Figure '7 and shows the arming pin and associated switch.

Figure 4, a sectional view taken on section 4--4 of Figure 1, shows the explosive release device for the parachute together with associated switches.

Figure 5, a sectional View taken on section 5-5 of Figure '7, shows the construction of the explosive release device utilized to release the legs .prior to erection.

Figure 6 is an elevation view showing the degenerally by the numeral 10. cludes a main transverse member l2, a spider vice in erected position with legs and antenna extended.

Figure 7 is a plan view of the device shown in Figure 1, including details of the leg-releasing means.

As shown in Figure 1, the complete assembly is similar in appearance to a bomb and because of its lighter weight is even more readily transported by aircraft. The housing is indicated The housing in- M and an upper shelf member l6. These three members are connected by longitudinal supporting members l8. A resiliently mounted shelf 20 is suspended from the transverse member l2 by shock supports 22. Above the transverse member l2 are mounted the weather-responsive devices consisting of the pressure-responsive device 24, the temperature-responsive device '26 and the humidity-responsive device 28. Mounted on the shelf 20 on the clock 30, the battery power supply 32, the relaxation oscillator 34and the radio transmitter 36.

Hingedly attached to the spider 14 are a plurality of legs 38 pivoted on pins 40. The legs 38 are spring-biased toward the nose portion 42 by means of powerful springs 44. The legs are held in the unerected position by means of retaining wires 46 held in place by the pin 92 of the explosive release device 48.

A yoke 56 is provided for carrying the station in a standard aircraft bomb-rack. After being released from an aircraft the device is supported by means of a parachute, normally stored between the legs 38 in the space 52, which limits rate of fall to approximately eight feet per sec-- ond. The parachute supporting line 54 connects the parachute (not shown) to the supporting rod '56. The other end of the rod 56 engages a parachute release device 58 which is mounted at the spider [4 at a point of great mechanical strength. Rod 56 is led into the interior of the station through tube 60 which forms part of the vertical. supporting structure. An arming switch 62 is attached to the parachute supporting line 54 by means of lead-line 64 and is released to apply battery power to the nose switches 66 at the time that the parachute opens. Nose switches 66 are effective to release the parachute when the weather station strikes the earth, through the operation of parachute release device 58.

The nose 42 fastened to traverse member [2 is shaped so as to offer litle resistance to motion through the air. The nose 42 is constructed of 3 thin deformable material such as light gauge metal and will normally be deformed upon striking the earth. such deformation aids in protecting the internal components from shock since the energy of impact is absorbed in the bending of the metal.

Mounted in close proximity to the inner surface of the nose 42 is a vertical telescoping antenna 61, designed to operate by gas pressure, mounted in a barrel 68. Pressure to elevate the antenna is generated in the explosive chamber erecting device connected to the antenna barrel 66 by the flexible conduit 12. The antenna barrel 68 is slidably mounted in the transverse member I2 and the spider member I4 in order to enable axial translation of the antenna upon inward deformation of the nose 42. In Figure l the antenna barrel 66 is shown in contact with the inner surface of the nose 42. However, it will be obvious to one skilled in the art that the antenna barrel need not actually be attached to the nose. The antenna and reservoir have been placed in the position shown in order that the center of gravity of the device may be as low as possible and also to accommodate the length of the antenna, which is appreciable even when in the unerected position. Relative motion of the reservoir and the antenna barrel 68 upon impact is taken up in the flexible conduit 72.

The nose switches 66 are placed at spaced intervals about the nose so that at least one switch is operated regardless of the angle at which the housing may strike the earth. The switches 66 are operated by the switch operators 14 on the outside of nose 42.

Figure 3 is a sectional view of the arming switch 62, consisting merely of a pin 16 normally housed in a bored hole 18. A single pole normally closed switch 80 closes the switch circuit upon the withdrawal of pin 16 by lead line 64.

Figure 4 is a detailed sectional view of the parachute releasing device 58. This device consists of a release pin 82, threading an eye on the end of rod 56. An explosive charge contained chamber 84 is fired by an electric fusible resistance link (not shown) which is energized by terminal 86. Two normally-closed

single pole switches

88 and 90 are released to make contact in two circuits upon the ejection of the pin 82.

Figure 5 shows the explosive release device 48 which is similar in construction to that shown in Figure 4. It utilizes a pin 92 engaging the leg releasing wires 46 and ejected by the explosive device 94. The explosive device contains a resistance firing element of a well known type not shown. A normally closed switch 96 and a normally open switch 96, the use of which will be described below, are released upon ejection of the in 92.

Figure 6 shows the weather station in the erected position as it appears during the transmission of a weather signal. Side panels I60 are shown to better advantage than in Figure 1. These are used to provide mechanical protection and to offer better streamlining.

The electrical portion of the device shown in Figure 2 consists of an electric clock of a well known type to control the erecting of the station and the switching of weather-responsive resistances into the grid circuit of a relaxation oscillator, relays to accomplish this switching, a relaxation oscillator and a transmitter controlled thereby as illustrated in Figure 2, the

switches

80, 88, 90, 96, and 98 are shown in the positions in which they are maintained by the

pins

16, 82,

and 92. These switches are positioned as shown at the beginning of the operating cycle and are in each case changed upon ejection of the associated pin by the operation of the fusible elements and 95. The clock consists of a clock winding I02 operated by a clock battery I03, a clock minute hand I 04 and an hour hand I06. The hour hand controls four contacts I08 spaced at three hour intervals. The minute hand controls terminals H0, H2, II4, H6, H8 and I20, controlling the operations to be performed in sequence. Relay I22 operates the explosive leg releasing device 48. Relay I24 operates the antenna elevating device 10. Relay I26 switches the pressure-responsive resistor into the relaxation oscillator circuit while relays I28 and I30 perform this function in the case of the temperature and humidity resistors respectively.

Numeral 24 indicates the pressure-responsive device consisting of a variable resistor I32 and the winding of a clamping device I34. The temperature-responsive device 26 includes a temperature-sensitive resistor I36 while the humidity-responsive device includes a variable resistor I38 and the winding of a clamping device I40. The clamping devices I34 and I46 are electromagnets which act to force the moving element of the associated resistor into firmer contact with the resistance strips during-- the period of transmission. Numerals 13, 85 and indicate the fusible resistance links controlling detonation of the explosive devices associated with the parachute releasing device, the leg erecting device and the antenna erecting devices respectively. Fusible link 85 of a arachute release device is operated by nose switches 66 in series with arming switch 80. Th fusible link 95 in the leg releasing device 46 is operated through contacts I08 and H0 of the clock 30 and contact 68 of the parachute release device 56. The fusible link 13 which sets off the explosive charge in the antenna erecting device 10 is energized by terminal II2 of the clock 30 and receives power through switch 98 of the leg releasing device 48.

Power for the filaments of the vacuum tubes and the fusible links is supplied by battery I42, filament power being controlled by contacts I44 associated with filament relay I46. Relay power is furnished from the relay battery I48. The contacts associated with the relays which are designated as I50, I52, I54, I56, I58, I60, I62 and I63, will be discussed in describing the operation of the electrical portion of the device.

By the means of the clock 30, resistors I32, I36 and I38 and the reference resistor I 64 are applied successively on output terminals I66 and I68. The latter terminals lead to the grid circuit of a relaxation oscillator 34. The relaxation oscillator includes a timing capacitor I16, vacuum tube I12, and grid-plate coupling transformer I14 which operates the plate circuit relay I16. The contacts I18 of this relay short out resistor I86 supplying some of the grid bias in the crystal oscillator portion of the transmitter 36. This breaks the transmitted wave up .into pulses.

Operation of the parachute suspension line 54 applies ten.- sion-t'o lead line 64 which-pulls the dowel 16 from the arming switch 62. Upon impact with the ground, nose switch operators l4 actuate one or more ofthe switches 66 to make contact resulting in the release of the parachute by the operation of the parachute releasing device 58. When the parachute pin 82 has been ejected from, the parachute release mechanism 58, the switch 00 on. the :parachute releasing device applies negative voltage from the relay battery I48 to the hour hand contact I08 of the clock 30. Atthe same time switch 90 on the parachute releasing device energizes the normally open contacts I50 of relay I22. The weather station normally will lie on its side until the minute hand I04 of the clock makes contact with terminal H0,

simultaneously with the completion of contact between the hour hand I06 and one of the contacts1I08J At such time the leg releasing relay I22 closes the associated contacts I50 resulting in the firing of the leg releasing device 48. Releasing of the legs causes the device to assume the position shown in Figure 6. It should be noted'that heavy leg construction is an advantage in performing this erecting, particularly when the nose member 42 has been more or less flattened by impact with the earth. The high rotational inertia of the legs about pins 40, articularly those legs not in' contact with the ground, enables them to carry through to the final erected position when put in motion by the urging action of the springs 44.

. Firing of the leg releasing device 48 causes the closing of the associated contacts 98 resulting in the energization of the contacts 54 of antenna erecting relay I24. At the same time contacts 96 open to prevent the leg releasing relay 22 from ever subsequently drawing power from the relay batter'yII48. It will be apparent from an inspection of 'the wiring diagram in Figure 2 that the. relay I46 is connected in series with the relays'I24, I26, I28, and I30, so that energization of the relays I24, I26, I28, and I30 by the minute hand I04 through the contacts II2, H4, H6, H3, and I also energizes the relay I46 to apply filament power to the several vacuum tubes. Contact between the minute hand I04 and contact II2-next causes erection of the antenna through the action of the antenna erecting relay I24 and the closing of contacts I54 which fires the antenna erecting device 10. At the same time, the closing of contact I52 switches the reference resistor I64 across terminals I66 and I68 leading to the grid circuit of the relaxation oscillator 34. Simultaneously with operation of relay I24 the relay I46 closes its associated contacts I44 applying filament power to the oscillator and transmitter portion of the station.

With" the reference resistor I64 in parallel with the .-c'apacitor I10 in the grid circuit of the relaxation oscillator 34, the oscillator will produce pulses at a rate dependent upon the value of the reference resistor I64. The pulse rate will be approximately two pulses per second. Pulses of current in the plate circuit of vacuum tube .I.'I2 cause interrupted action of the plate relay oflthe. grid. bias resistor of thefcrystal oscillator the transmitter 36. Since the reference resistor I64 has a fixed resistance, its calibrated pulse rate is known and in actual operation of the devicemay beused to determine whether the associated relaxation oscillator circuit is still in calibration. The operation of the oscillator and use of the reference resistor is described in greater detail in the patent application ofLowell et al. mentioned above.

Following transmission of the reference pulses, the minute hand I04 moves away from terminal II2 removing the reference resistor I64 from the circuit and moves into contact with terminal I I4 closing the pressure-responsive relay I26. Closing of the latter relay causes the circuit to be made through contacts I56 to apply the resistor I32 across terminals I66 and I68. At the same time the circuit is completed through contacts I58 causing operation of the clamping device I34 which, as stated above, is efiective to reduce contact resistance between the moving elements of the variable resistor I32. .The use of a clamping device is old in the art and will not be discussed in detail. With pressure-responsive resistor I32 in the circuit of the relaxation oscillator 34 the transmitter will transmit pulses at a rate dependent upon the existing resistance of this resistor. The pulse rate is interpreted at the receiving station in terms of barometric pressure.

Subsequently, the minute hand I04 makes contact with terminal II6 on the clock 30 causing contacts I60 of relay I28 to switch the temperature-responsive resistor I36 across terminals I66 and I68. This produces a transmitted pulse rate dependent upon the temperature existing at the device at the time of transmission. Next, the making of a circuit at terminal II8 of the clock through the action of relay I30 and contacts I62 switches the humidity-responsive resistor I38 into the circuit of the relaxation oscillator 34. A clamping magnet I40 operated in the same manner as discussed in connection with the clamping device I34 is energized through the contacts I63 on relay I30.

Finally, the reference resistor I64 is again cut into the relaxation oscillator circuit bymeans of terminal I20 of the clock 30. Upon completion of the transmitting sequence just described, the

' to one skilled in the art that the program can 11.6. which periodically shorts out portion I80 be changed to suit the specific requirements by proper spacing of terminals IIO through I20. It will also be obvious to one skilled in the art that other information in addition to pressure, temperature and humidity may be included in the program by the addition of clock contacts, relays and a condition-responsive resistor similarly connected.

It will be seen from above that a weather station constructed in accordance with my teach.- ings will enable impact to be absorbed by deformation of the light nose portion while the construction of the antenna mountingand the erecting device is such as to enable effective erection and reliable transmission in spite of the deformation occurring in the nose portion. It

will also be seen that I have provided an interlocked switching system which insures proper sequence of the erecting and transmitting functions regardless of the time indicated by the clock at the time the weather station is dropped.

When the station is to be used only as a beacon, the radio transmitter and its control mechanism may be simplified merely to transmit a signal which may be used to guide, for example,

7 other craft equipped with radio director-finding apparatus.

While I have shown and described but one embodiment of my invention, it will appear to those skilled in the art that various changes and modifications may be made without departing from my invention, and I, therefore, aim in the appended claims to cover all such changes and modifications as fall Within the true scope of my invention.

What I claim as nev. and desire to secure by Letters Patentv of the United States is:

1. A portable radio transmitting station designed to be dropped from aircraft comprising a bombl ike housing, a light gauge deformable convex nose on said housing, a radio transmitter including a telescoping antenna operated by gas pressure, an antenna barrel housing said antenna, said antenna barrel being slidably mounted in alignment determining apertures in said housing and extending into proximity with the inner surface of said nose, a rigidly-mounted gas reservoir within said housing, a flexible connection between said reservoir and said antenna barrel, whereby axial translation of said antenna barrelupo-n inward deformation of said nose portion is permitted and the likelihood of damage to said antenna upon impact with the earth is reduced.

2. A portable radio transmitting station designed to be dropped from aircraft comprising a bomblike housing, a light gauge deformable convex nose on said housing, the center of gravity of said station located near said nose, legs for the erection and support of said housing, said legs being hingedly attached about the waist of said housin at a level above said center of gravity and each arranged to swing in a plane which includes the axis of said housing, retaining means to hold said legs along said housing in a direction away from said nose, biasing means to urge said legs toward said nose to erect said housing upon release of said retaining means, said legs being of large rotational inertia whereby the erection of said housin is facilitated in spite of deformation of said nose upon impact with the earth.

3. A portable automatic radio transmitting station designed to be dropped by parachute from aircraft comprising a parachute releasing device and erectin devices required to be operated in a predetermined order, means initiated upon impact with the earth to operate said paratchute releasing device, a clock having switch means to cause the operation of each of said erecting devices in sequence at a predetermined true time, normally open interlock switches operated by said parachute releasing device and each of said erecting devices respectively, said switches bein closed upon operation of the associated device, said interlock switches being so connected to said clock switch means that the operation of each of said interlock switches is prerequisite to the operation of the erecting device designed to be operated next in order, whereby said clock is ineffective to operate said erecting devices except in the predetermined order regardless of the time ind cated by said clock at the time of dropping said station.

4. A portable automatic radio transmitting station designed to be dropped by parachute from aircraft comprising a parachute releasing device, erecting devices and a transmitting de vice required to be operated in a predetermined order, means initiated upon impact with the earth to operate said parachute releasing device, a clock having switch means to cause the operation of each of said erecting devices and said transmittin device in sequence at a predetermined true time, normally open interlock switches operated by said parachute releasin device and each of said erecting devices respectively, said switches being closed due to operation of the assoc-iated device, said interlock switches being so connected to said clock switch means that the operation of each of said interlock switches is prerequisite to the operation of the erecting device designed to be operated next in order, whereby said parachute releasing device and each of said erecting devices operates only in a predetermined order and whereby all erecting functions are performed before energization of said transmitting device regardless of the time indicated by said clock at the time of dropping said station.

5. A radio station as claimed in claim 4 including an arming switch operated upon dropping of said station from aircraft, said arming switch being effective before it is operated to prevent said clock switch means from energizing said erectin devices or said transmitting device.

6. A portable radio transmitting station designed to be dropped by parachute from'aircraft comprising a bomb-like housing, an erecting device controlled by an erecting device interlock switch, a parachute releasin device, means effective upon contact of said station and the earth to operate said releasing device, said parachute releasing device including a dowel pin adapted to be axially translated to perform the releasing function, an erecting device interlock switch comprising a spring biased operating plunger, said plunger being positioned to move into the space normally occupied by said dowel pin to operate said interlock switch, whereby closing of said interlock switch and operation'of said erecting device is not possible until ejection of said dowel pin.

'7. An air-launched radio transmitting section comprising a parachute, an extensible antenna, a radio transmitter, a time-controlled switch for determining the periods of energization of said transmitter, and electrical control system comprising switch gear responsive to impact with earth for controlling release of said parachute, extension of said antenna and functioning of said time-controlled switch, and interlock switches included in said system t ensure'release of said parachute and extension of said antenna in predetermined sequence.

ROBERT P. BENNETT.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Arenstein Feb. 21, 1950