US3122743A - Collapsible radar reflective device - Google Patents

Description

F. R. VLASIC COLLAPSIBLE RADAR REFLECTIVE DEVICE 4 Sheets-Sheet 1 Feb. 25, 1964 Filed April 20, 1956 BA N N ER PORTIONS REFLECTIVE SURFACES IN V EN TOR. fie/9M4. A. 1/1,? /c

Feb. 25, 1964 F. R. VLASIC COLLAPSIBLE RADAR REFLECTIVE DEVICE 4 Sheets-Sheet 2 Filed April 20 INVENTOR. F/EH/VA 3 V6195 C FTTOE/VE S F. R. VLASIC COLLAPSIBLE RADAR REFLECTIVE DEVICE Feb. 25, 1964 4 Sheets-Sheet 3 Filed April 20, 1956 IN VEN TOR.

Ff/M/K E Vi 175/6 BY WW Feb. 25, 1964 F. R. VLASIC COLLAPSIBLE RADAR REFLECTIVE DEVICE 4 Sheets-Sheet 4 Filed- April 20, 1956 IN VEN TOR.

United States Patent QOLLAPSlELE RADAR REFLECTIVE DEVECE Frank R. Vlasic, New tlarlisle, llhio, assignor to the United States of America as represented by the Secretary of the Air Force Filed Apr. Zll, 1956, fll'. N 57%,696 6 Claims. (til. 343-313) (Granted under Title 35, US. Code (1952), see. 266) The invention described herein may be manufactured and used by or for the United States Government for governmental purposes without payment to me of any royalty thereon.

The present invention relates to an apparatus adapted for use as a target or decoy device in aircraft operations, and more particularly, in countermeasure Operations re lates to a collapsible decoy missile for carriage and release by an aircraft to simulate explosive missiles and weapons dropped in the same vicinity.

In aircraft countermeasure operations, the need has arisen for a decoy device or a missile which is confusingly similar to explosive missiles or weapons dropped or released in the same area in order to distract ground observer units away from the actual weapons. Ideally, of course, mock bombs or blank missiles could be utilized; however, the space required to carry such decoys in great quantities negates their use, and furthermore would entail comparatively high expense. In the main, chaff dispensing units have been in common use, but have been found to be inadequate to confuse the more accurate observer units, particularly improved radar measures. Accordingly, the subject invention is designed to correct the foregoing difficulties in a unique manner in that it is compact and can be released in great quantities, yet will open upon release to simulate visually and electronically, both in trajectory and shape, objects and weapons dropped or released in the same vicinity.

It is a subsequent and primary object of the present invention to provide a decoy device of collapsible construction which is self-opening upon release and which has low drag characteristics in relation to its maximum area and light weight to simulate in trajectory and shape weapons or missiles dropped in proximity thereto.

It is another object to provide a plurality of collapsible decoy devices which may be folded into compact units or clusters for storage within a small area of an aircraft.

Another object is to provide a collapsible decoy device which may be compactly stored, yet will accurately simulate in trajectory and shape larger size missiles upon release.

It is another object to provide a deployment apparatus which may be combined with the decoy device to retain the decoy device in collapsed position in flight and to cooperate with a bomb release mechanism to dispense the decoy at a predetermined time.

It is a further object to provide a collapsible device whose elements may be regulated in size and in weight to conform to the trajectory and rate of fall of different types of missiles, and further readily conformable in contour to correspond with the contours of different forms of missiles or weapons.

A still further object of the present invention is to provide a collapsible decoy device in combination with a deployment apparatus which may be adjusted to open the decoy device at a predetermined distance after release from the aircraft.

Further objects and advantages of the present invention will be more fully set forth, reference being made to the following detailed description of a preferred form of the invention and to the accompanying drawings in which:

FIG. 1 is a perspective view illustrating the decoy 3&22343 Patented Feb. 25, 1964 ice :13 device in unfolded, extended position upon separation from the deployment apparatus;

FIG. 2 is a side plan view showing the decoy device in extended open position;

FIG. 3 is a top plan view of the collapsible frame of the decoy device;

FIG. 4 is a perspective view illustrating the deployment apparatus and the decoy in assembled position for attachment to the bomb bay of an aircraft;

FIG. 5 is a perspective view illustrating the disassembled deployment apparatus, along with the decoy device.

Broadly, my invention comprises a collapsible banner 46 having a plurality of radial reflective surfaces 47 sup ported on a collapsible framework it) with supporting means 11% holding the reflective surfaces 47 in extended position after release from an aircraft as shown in FIG. 1. A deployment apparatus 50 is further provided for suspension of the decoy device in folded position, preferably from the bomb rack of an aircraft, the apparatus 5% being operative to permit deployment and outward extension of the decoy at a predetermined interval after release from the aircraft.

Referring more particularly to the drawings, there is shown in FIGS. 2 and 3 the collapsible frame or head member made up of a streamlined nose portion or cone 11 and a tubular stem or shank portion 12 which is passed over a plug extension member 13 of the cone 11 and is attached thereto by means of three studs 14 equally spaced about the shank 12. In addition, substantially midway along the tubular stem portion 12, supporting means 19 are provided which include three U-shaped channels or bracket retainer plates 20 welded at equally spaced intervals around the stem 12 in which three support members or spreader arms 21 are pivotally mounted by means of bolt 22 positioned across the channel 2t outwardly biased retainer springs 23 are anchored by means of fasteners 24 at the forward end of each chan nel 2% to swing the arms 21 from a hat, forwardly pro" jecting position along the stem 12 out into the afrstrean'i and into extended position as shown in FIG. 2, and to maintain the spreader arms 21 in extended position guy Wires or cables 28 are provided with terminal shackle members or couplers 29, one being swaged onto the guy wire at each end for interconnection of each spreader arm 21 to the cone H. For attachment to guy wires 28 each spreader arm is provided with a half clamp 30 at its distal end and bolts 31 passed through the clamp 39 and shackle 29; the rearward end of the nose 11 is provided with three equally spaced slots 15 axially aligned with the spreader arms 21, and the bored portions 16 are in turn reamed transversely into each side of the slots 15 for insertion of pins 17 to hold the shackle 29 in swiveled position within each slot 15.

At the forwmd end of the tubular stem 12, a cylindrical weight 33 or other suitable means can be inserted to vary the weight of the frame or to balance it as desired, and may be attached in position by means of a stud 34- threaded through the stem 12.

There is shown also in FIG. 1 and partially in FIG. 2. the flexible banner 46 made up of a tubular cloth member 41 closed at its rearward end a3 and having a funneled or flared portion 42 at its forward and passed over the rearward end of the stem 12, and three equally spaced reflective cloth surfaces &7 attached to the tubular portion for alignment with the spreader arms 21. Each reflective surface 47 is provided with a header strip 44 and aluminum insert 45 placed within the strip 44 for attachment by means of brackets 38 along the length of the spreader arm 21. Extending rearward-1y from each header strip and substantially parallel to the tubular portion 41 are ribbons or cloth strips =48 maintained in spaced alignment by means of an outer Webbing or heavy ribbon 46 tapering rearwardly and inwardly from the distal end of each header strip 4 to the rear end 43 and a plurality of transverse retaining bands or ribbons 49 sewn across the ribbons 4d at spaced intervals along the axis of the tubular portion 41 thereby forming a network or mesh of longitudinal and transverse strips mutually retaining one another of spaced relationship. The ribbons 48 and 49 and outer ribbon 4-6 are metallic coated to provide reflective surfaces and can be arranged in any desired shape or configuration so that the side view of the banner in flight will simulate the actual objective. In this way, a very lightweight banner is attained by using a min mum number of surfaces and by forming a network of ribbons rather than a continuous cloth section. Also, in using a minimum amount of material the banncr is very compact yet is hishly reflective when extended and has a low drag due largely to the minimum number of surfaces and inward taper of the outer webbing portion 46.

The decoy device is folded into collapsed position for storage in the bomb rack of an aircraft (not shown) by means of the deployment apparatus t as shown in FIG. 4. As illustrated in MG. 5, the deployment apparatus consists of a deployment bag 5'1 for housing the flexible banner portion 4th, a parachute pack 52 carried at the rear end and exteriorly of the sack 51 which is provided with a release cord 53 and inclosed chute 54; and a rip cord 55 and snap hook 56 interconnecting the chute pack 52 and aircraft. In assembly, the banner ll) is connected at its rear end 43 by means of a break line 58 (not shown) to the deployment bag 51 and packed into the bag 51. The spreader arms 21 are then swung forwardly and the release cord 53 is looped around the arms and attached at its free end by means of a pullout pin 59 provided on the release cord for insertion into the eyes 59a. Tie cords 6d are then tied over the release cord and collapsed arms at spaced intervals along the device, as shown in FIGURE 4-. The assembled countermeasure device may then be suspended from the bomb rack in the aircraft by means of lugs 32 provided on the stem 12 for attachment to the bomb release mechanism, and the snap hook 56 may be connected within the bomb rack.

In operation, either a single decoy device or a cluster of devices may be suspended Within the bomb bay area. Upon actuation of the bomb release mechanism each decoy device It? may be dropped out of the bomb bay as in a normal bombing operation, either one at a time, in predetermined sequence or in salvo, releasing each pilot chute 54 fro-m the ribbon 55 and pilot chute pack 52 which remain with the aircraft. Due to the downward shock of the decoy device, the release cord 53 will act to rip apart each tie cord 61 along the device and finally release the pull-out pin 59 to free the spreader arms for outward extension under the influence of the outwardly-biased springs 23. The open pilot chute 54 will tien act to remove the pack from the banner ill, the rear end 43 of the banner being pulled rear'wardly by the break line 58 to its full length at which time the cord will break and the decoy device will fall freely, starting with a horizontal velocity slightly less than that of the aircraft. Of course, other suitable deployment means may be utilized in freeing the decoy device for its descent; however, the preferred form has been found to be most advantageous in that release can be obtained at any desired distance from the aircraft and without danger to the aircraft itself or its personnel. In addition, when it is desired to release a cluster of decoy devices adequate dispersal of the decoy devices is gained before each bannor is extended to its outward position thereby preventing entanglement of the devices. In descent, the tubular portion ll will tend to remain rigid due to the air pressure introduced within the flared portion 42, but will not be suflicient to increase the drag material. Depending upon the weight and size of the banner, the frame can be lanced or varied in weight by means of the weight to obtain the prope trajectory and rate of fall. As

een in flight, either visually or by means of radar ne outline of the preferred form would be that of a omb or a missile from a distance. is previously ment'cned, the in ape can be varied to correspond with many s of weapons.

For purposes of exempliiication, particular embodiacc rding to the best present understanding thereof. However, it will be apparent that many changes and modifications in the arrangement and construction of the parts thereof may be resorted to without departing from the true spirit and soo e of the invention, as set forth in the accompanying claims.

I claim:

1. An airborne decoy apparatus adaptable to be released from an aircraft to simulate the trajectory and form of weapons released in the vicinity thereof, comprising: frame menber variable in weight having at least three radial arms pivotally connected to said frame and forwardly projecting therefrom, spring members to urge said arms to an outward extended position and brace members to limit the outward movement of said arms to an extended position with respect to said frame; and a flexible banner rearwardly extending from said frame including a tube portion flared outwardly at its forward end and closed at its rearward end, and a plurality of radial reflective surfaces connected to said tube, each surface relating to one of said radial arms and made up of a header strip connected to said arm, an outer reinforced ribbon tapering rearwardly and inwardly from said strip for connection with said tube and a network of ribbons pass rcarwardly between said tube portion and said outer ribbon.

2. in an aircraft countermeasure system wherein deployment means are provided on an aircraft to constrain a target in collapsed position in flight and to cooperate with a bomb release mechanism to release said target at a predetermined distance from said aircraft, said target comprising in combination with said deployment means: a collapsible frame having means to dispose said device in a downward trajectory, and associated support means; and a flexible banner portion including a central tubular member and a plurality of equally spaced reflective surfaces radially disposed about said tubular member and made up of a network of reflective cloth strips, each network connected at its forward end to said support means and tapering rearwardly and inwardly for connection with said tube, said support means being biased to urge said surfaces outwardly to an extended radial position upon separation from said deployment means and said tubular member being inflatable to extend said reflective surfaces rearwardly so as to visually and electronically simulate the trajectory and shape of weapons dropped in the vicinity thereof.

3. In an aircraft countermeasure system wherein a deployment apparatus is provided for the predetermined release of a collapsible decoy device from an aircraft and includes a deployment bag, a chute pack provided with a release cord and enclosed chute carried by said bag, and a rip cord and snap hook interconnecting said chute and said aircraft, said decoy device comprising in combination therewith: a collapsible frame having a streamlined nose portion, a balanced tube portion and outwardly-biased support means including a plurality of folding arms circumferentially spaced about said tube and restrained in collapsed position by said release cord encircling said arms and said support, spring members to urge said arms to an extended radial position from a collapsed position along said tube, and braces interconnecting said nose and said arms to retain and support said arms in extended radial position; and a reflective cloth banner housed within said and provided with an inflate le tube portion extending rearwardly from said balanced tube, and a plurality of radial reflective surfaces connected to said inflatable tube and extending radially and outwardly for alignment and support by said related arms, each surface having an outer peripheral ribbon portion verging rearwardly and inwardly to the rearward end of said tube from its connection with one of said arms, a plurality of spaced ribbons extending intermediate said outer ribbon substantially parallel to said tube, and a plurality of retaining bands connected transversely across said ribbons and outer ribbon to maintain said ribbons in normal spaced relationship with said tube.

4. A collapsible countermeasures device adapted after launching from an aircraft for free flight with a trajectory simulating a missile and the like and having a distant visual and radar echo configuration simulating a missile comprising, a central supporting member, a plurality of arms hinged to said supporting member and adapted to move from a folded position parallel to said supporting member to a free flight position substantially normal to said supporting member, yielding means for moving said arms from their folded to their free flight position, a flexible fabric tube secured to said central member and extending rearward therefrom, said fabric tube being adapted to be inflated by ram air pressure during free flight of said device, a border tape secured at one end to the outer end of each of said arms and secured to said fabric tube adjacent its rearward end, a plurality of ribbons secured in closely spaced relation to each of said arms substantially normal thereto and the terminal ends of said ribbons being secured to said border tape a plurality of ribbons extending parallel to each arm in spaced relation and secured at their inner ends to said fabric tube and at their outer ends to a border tape, said ribbons and associated border tapes forming banner surfaces of controlled aerodynamic porosity, said banner surfaces supplying free flight support and directional stability to said device, and a radiant energy reflective coating on said ribbons.

5. In an aircraft countermeasure operations decoy device, of the class described, a collapsible rigid radial support, a collapsible radar reflective banner carried by said support comprising an elongated inflatable tube member open at a forward end and closed at its rearward end, a plurality of substantially equally spaced flexible radar reflective surfaces connected to said collapsible rigid radial support and to said tube member and extending radially outward in different directions from the central axis of said tube member and converging rearwardly from said collapsible rigid support toward said rear-ward end of said tube member, each of said rearwardly converging surfaces including a peripheral outer heavy flexible reinforcing tape portion and a network of spaced flexible parallel radar reflective strips disposed parallel to said tube member and tied together intermediate their ends forming the radar reflective body thereof, whereby each surface is adapted to present a minimum drag in proportion to its light weight and maximum area in different radial planes about said tube member.

6. In a radar reflective device of the character described, a flexible collapsible multibanner device comprising a flexible collapsible inflatable central tube portion having an open forward air intake end and a closed rear end, and a plurality of radar reflective cloth surfaces con nected to said central tube portion along its length at substantially equal degrees about the longitudinal axis of said tube and extending radially outward from said central tube portion in radial planes extending through the longitudinal axis of the central tube portion, each surface comprising an outer peripheral ribbon portion verging radially outward from said forward end of said tube portion then inclining gradually inwardly and rearwardly toward the rearward end of said tube portion, a plurality of parallel radar reflective ribbons connected between said outwardly verging and said inwardly and rearwardly inclined portions of said outer peripheral ribbon substantially parallel to said tube portion, and a plurality of flexible retaining bands connected to and extending transversely across said ribbons for maintaining said ribbons in said spaced parallel relationship.

References Cited in the file of this patent UNITED STATES PATENTS 2,419,549 Griesinger Aug. 29, 1947 2,447,972 Weinert Aug. 24, 1948 2,455,469 Casper Dec. 7, 1948 2,483,402 Cotten Oct. 4, 1949 2,489,337 Sperling NOV. 29, 1949 2,490,793 Fleming Dec. '13, 1949 2,639,426 McAuley et al May 19, 1953 2,674,693 Millett et al. Apr. 6, 1954 2,763,002 Fitzgerald et al. Sept. 11, 1956

Claims (1)

1. 5. IN AN AIRCRAFT COUNTERMEASURE OPERATIONS DECOY DEVICE, OF THE CLASS DESCRIBED, A COLLAPSIBLE RIGID RADIAL SUPPORT, A COLLAPSIBLE RADAR REFLECTIVE BANNER CARRIED BY SAID SUPPORT COMPRISING AN ELONGATED INFLATABLE TUBE MEMBER OPEN AT A FORWARD END AND CLOSED AT ITS REARWARD END, A PLURALITY OF SUBSTANTIALLY EQUALLY SPACED FLEXIBLE RADAR REFLECTIVE SURFACES CONNECTED TO SAID COLLAPSIBLE RIGID RADIAL SUPPORT AND TO SAID TUBE MEMBER AND EXTENDING RADIALLY OUTWARD IN DIFFERENT DIRECTIONS FROM THE CENTRAL AXIS OF SAID TUBE MEMBER AND CONVERGING REARWARDLY FROM SAID COLLAPSIBLE RIGID SUPPORT TOWARD SAID REARWARD END OF SAID TUBE MEMBER, EACH OF SAID REARWARDLY CONVERGING SURFACES INCLUDING A PERIPHERAL OUTER HEAVY FLEXIBLE REINFORCING TAPE PORTION AND A NETWORK OF SPACED FLEXIBLE PARALLEL RADAR REFLECTIVE STRIPS DISPOSED PARALLEL TO SAID TUBE MEMBER AND TIED TOGETHER INTERMEDIATE THEIR ENDS FORMING THE RADAR REFLECTIVE BODY THEREOF, WHEREBY EACH SURFACE IS ADAPTED TO PRESENT A MINIMUM DRAG IN PROPORTION TO ITS LIGHT WEIGHT AND MAXIMUM AREA IN DIFFERENT RADIAL PLANES ABOUT SAID TUBE MEMBER.

Images