US2482130A - Flying target unit - Google Patents

Description

L. A. sKlNNER FLYING TARGET UNIT Sept. 2o, 1949.v

3 Sheets-Sheet l Filed May 18, 1942 W n im .fm j n -m i E L sept. 2o, 1949. A. SKINNER FLYING TARGET UNIT 3 sheets-sheet 2 Filed May 18, 1942 L E: Elie H Skinner Sept. 20, 1949. 1 A. sKlNNER FLYING TARGET UNIT :s sheets-shea 3 Filed May 18. 1942 Le Ehe El Eldnner Patented Sept. 20, 1949 UNITED STATES PATENT *OFFICE FLYING TARGET UNIT Leslies.. Skinner, united statesnrmmwashingtn,4 D.. C.,y assigner to the United Statesof lAmerica as represented by the Secretary of War Application Mayv I8, 1942', Serial No.. 4433410 1. claim. (c1. zia-1.05.4).

(Gran-ted undergtheact of Mai-cli 3, 1883; as

amended April- 30, 1928;. 3??.0 O;r G. 757)' The invention describedL herein may be manufactured' and used' by' or for. the Governmennt forl governmental purposes. without the payment to me of any royalty thereon.

This invention pertains to atarget for practice .in antiaircraftv ring and more particularly to,- a rocketv propelled'v target intended tcv simulate the ilight of. anairplane.-` e

In conventional antiaiicrait-I practice sleeve targets towed. by airplanes? andy in. some cases remotely controlled". target airplanes have been employed. The first method has the obvious disadvantage that thetowing. plane isY restricted to a fairly straight path andl that the sleeve target will likewise-follow a relatively straight and easily predictable path;A The-v elernent of uncertainty essential to the usefulness ci practice firing is entirely lacking. The second method' mentioned above is impractical by reasonr of the expense of the equipment required and the probability of totally destroyingv the same the event of a direct hit.

It is therefore an obiect of this invention. to provide a-n antiaircratv target which by reason of the suddenness of" its appearance.v and the character of its, Aflight will furnish. valuable practice forj defenseagaiinst low dying aircraft.

It is a further object ta produce au target which is, economical to produce.. ship, and maintain, and one whichs has; a salvage value after use..

The: exactv nature off. the invention as wellv as other objects and advantages. thereof will clearly appear from a description of a preferred embodiment as showin the' accompanying drawing in which:

Figure l is` a longitudinal sectional view of a target, rocket constructed accordingV to my invention.

Figure 2 is a cross sectional view on the I-in'e 2--2 of Fig. 1. l

Figure 3 is a `plan; view of the charge supporting diaphragm. W

Figure 4 isa cross sectional view` on' the line 4-4 of Fig. 3.

Figure 5 is a View similar to a portion of Fig. 1 showing a Inodied charge supporting and closure means. I Y Figure' 6 is a plan View 0f thier target base plate,

Figure 7" is an oblique view of the target plate securing' means. l

Figure 8 isa side elevational View partially in section showing a modified" form of' target. rocket.

Figure 9 is a front end' elevational' View of. the rocket closure shown in 8, the ogival plug being removed'.

Figure 10 is. anV oblique view 'of the ogival` plug.

Figure l1 is an end. elevational View of the. iin

assembly.v

Figure 12 is a.. View to Fig. 8.- showi'ng a modified forni of target. Y f

Figure 13 is a partial cross sectional. view of one of. the target plates of the Figure. 12. rocket on the lineY |.3.| 3 of. Fig..12.'

Figure le.` is a. longitudinal sectional. view of a primer Which might be used in any of the rockets.

lZigu-rey 15 is an enlarged longitudinal. sectional View -of the front. end-oi the motor tube shown in Fig. 12.

Referring tothe drawing by characters of reference, there is shown inFig. 1 a rocket adapted toserve as any antiai-rcrat target.. This` rocket com-prises three main units, a motor tube a body tube 2, and a plurality of. readily visible target plates 3. The motor tubezt is formed with a suitably constricted. portion 4;.at its. rear end andv is' ilared` outwardly therefrom to form a discharge nozzle 5; Contained vwithin the motor tube l is a motor charge assembly comprising a charge supportingcage 61 and a plurality of axially perforated sticks 'lV of charge (ior'iiioo'sitionV secured thereon. The cage l6' may be formed by aplurality of headed rod members 8 welded. vor'otherwise secured to a ring 9,' or any'l of the charge supporting means shown in mycopending applications. Serial? No. 411,512, filedvv September 19, 1941 (now Patent No. 2,446,560, issued May 12, 1948) may be used. As shown in the drawing one of the charge units is slipped over each of the rod members and the head l0 of each of the rod members is engaged inone of the apertures I in the charge supporting diaphragm which comprises a pair of plates l2' and I3. In plate f2: a plurality of radial notches Il, have been formed in spaced relation about the circumference and are adapted to en- 'gage the Shanks of the rod members. In the plate` f3 registeringl apertures Ha oi keyhole cross section have been formed', the circular part of the keyhole aperture being of suicient diameter to admit the enlarged head I of the rod members 8 while the other portion will register with the notch II and, like that notch, Will just pass the shank of the rod members 8. The plates may be secured to each other by spotwelding or other means to aid assembly, although such securing is not strictly necessary. 'I'he composite plate is assembled to the cage structure by engaging one of the rod members in. each ofhthe notches with the head of the r'od member'seated in the enlarged portion'l Ia.

The forward end of the motor tube I is provided with external threads I4 adapted to engage the internal threads I 4a formed in the rear end of the body tube 2. A plate I5 has been Welded or otherwise secured near the rear end of the body tube and the charge supporting plates are secured in the motor tube by clamping engagement between the front end face of the motor tube and the plate I5. The body tube 2 is extended forwardly a suiiicient distance to insure stable flight and is provided with a `counterbalance weight I6 secured in the front end thereof to also serve as a streamlined closure therefor.

An alternate method of joining the tubes and supporting the charge units is shown in Figure 5. In this modification the motor tube and body tube are joined substantially Aas before but no plate has been provided in the rear end of the body tube.. A circumferential groove I1 has been provided near the front end of the motor tube. a cage supporting plate I8 similar to that previously discussedbut of smaller diameter is received inside the" motor tube, and a cup-like obturator I9 is received betweenthe plate I8 and a plate 28. A spring snap ring 2I is engaged in the circumferential ygroove in front of the plates I8 and 2l)` and the assembly is clamped together by means of a bolt 22 threadably engaging the plate I8 and drawing a clamping bar 23 up against the forward edge of the spring snap ring.

The motor body isprovided on its outer surface with a plurality of forwardly facing plateengaging hooks or clips 24. Each group of hooks is spaced longitudinally of the motor tube in a straight line, a plane including all of the hooks of one line also including the axis of the tube. These lines of hooks are spaced equally about the circumference ofthe tube to provide for as many target plates as may be desired, four being shownin the drawing.

The target plates 3 are of generally semicircular shape, each being formed from a pair of semi-circular plates of light sheet metal 25 and 26, each slightly dished .and secured together about the circumference byv means 'of a roll seam 21. Hair pin-like braces 28 of square steel bar stock are provided insidethe target plates and secured thereto by spot vwelding or other similar means. A target base 29 shown separately in Figure 6 is inserted between the straight edges of the target plates and welded or otherwise secured thereto. The target base is provided with a series of symmetrically located D shaped apertures 30, a pair of such apertures being spaced apart by a bar 3| of unremoved metal adapted to be engaged by one of the target engaging hooks 24. As many pairs of such apertures are provided as there are hooks cn the motor bodi7 and the bars 3l are spaced in the same relation as the hooks, being also symmetrically located with regard to the ends of the target base. It will be seen that the composite target' plate may 4 be secured to the motor body simply by engaging one of the bars 3l beneath each hook 24 and sliding the target plate to the rear into contact with the base of the hooks. The symmetrical location of the hooks and apertures makes it immaterial which end of the target plate faces forwardly after application to the body.

One of the greatest advantages of this construction is that the rocket body and target platesmay be shipped :and stored separately in which condition-they may be packed with maxlimum economy of space. vAnother advantage is vthat on impact with the ground after flight the damage may be localized as the target plates will be-freed from the body and a maximum amount of material may be salvaged for reuse.

Figure 8 illustrates a modiiied form of target rocket which has certain advantages from the Vviewpoint of economy in construction.

This modification utilizes a motor tube 35 which is in general the same as that discussed in the previously described modication. In this type of construction the body tube and counterbalance `Weight are not needed as the target plates are secured about the rear end of the motor tube and Yextend rearwardly therefrom. The forward end of the motor tube may be closed as discussed in the previousmodic'ation although the closure shown in section in Fig. 8 and in end elevation in Fig. 9 is deemed preferable. This closure is similar to the modiiied form discussed in connection with Fig. 5in that a circumferential groove 36 formed in the inner wall of the motorv tube receives a spring snap ring 37.v This snap ring also engages afgroove 38 formed in the outer wall of a charge supporting diaphragm 39 to which Vis secured the charge supporting plate 40 and cupi-like obturator 4I.V The groove in the diaphragm is of suicient depth to permit the snap ring 3l to be contracted thereinto and a cutaway portion 42 is provided to permit the inturned ends 43 on the snap ring to be grasped With pliers or a similardevice in effecting that purpose. `When the charge has been secured to the diaphragm the snap ring may be contracted and the assembly inserted into the motor tube until the snap ringcan expand into the groove in the wall of the motor tube. As thegroove 36 has Yless depth than the radial dimension of the snap ring it will be evident that the diaphragm will then be securely held against longitudinal movement. `An ogival plug 44, shown in Fig. 10, of wood or similar material has a portion 45 of reduced diameter adapted to be received in the end of the motor tube and a. further portion of reduced diameter adapted to be received within the end of the diaphragm 39. VGrooves 46 have been provided to receive the inturned portions 43 of the snap ring and a tongue 4l has beenl provided for reception between those inturned portions. Itwill be seen that when the ogive is in place it will be impossible for the snap ring to be contracted and hence the ogive assists in maintaining the closure. The ogivemay be conveniently secured in place by means of wood screws 48 penetrating the wall of the motor tube and engaging the ogival plug.

A plurality of equally spaced plate supporting tubes 49 have been welded or otherwise secured to the exterior of the motor tube in axially parallel relation to the axis thereof. Each individual target plate comprises a tubular base 58 adapted to be closely received in one of the tubes 49 and provided with a plate 5I welded or otherwise secured to the tube as best shown in the end elevation in Fig. 11. The base tube 50 is inserted in the supporting Vtube lll` in suchaposition that a radial line passing through the'axis of themotor tube and of the base tubewill be parallel. to the plane of the ,target plate. Obviously. the target plate might be secured to the base tube in such a manner` as to depart-radially therefrom rather than tangentiallyasshown in which case the plane of the plate should be radial with relation to the axis of the motor body. The base tube may be conveniently secured inplace by means of a cotter 52 inserted through matching holes formed in the supporting tube and base tube. It is contemplated that the rearvends of the base tubes may be braced to each other by forming in the end of each tube a diametral slot 53 in which a brace ring 54 may be received and retained by cotters 55 passing through the base tube and the brace ring. In the event that further bracing of the target plates is needed it is contemplated that stabilizing braces 56 may be riveted in place between the plates.

It will be noted that this construction, while providing for target plates in the rear of the expansion nozzle, offers little or no obstruction to the proper expansion of the gas blast from the rocket nozzle.

Figure 12 shows another modification in target construction and attachment. The motor tube 6U is similar to the tube 35 in the Fig. 8 modification except for the omission of the target supporting tubes 49. A single target supporting tube 6| is received over the rear end of the motor tube 6U and secured thereto by brazing, welding, set screws or other equivalent means which will insure that the iin supporting tube forms a coaxial elongation of the motor tube. At spaced locations on the periphery of the supporting tube 6I plate engaging hooks 62 have been secured. These hooks are similar to and are located in similar manner to the hooks 24 on the motor tube I of the embodiment shown in Fig. 1. The target plates 3 of the Fig. 1 modication could be received on the hooks 62 but in the interest of manufacturing economy a modified plate 63 has been provided for this embodiment. This plate is shown in place in Fig. 12 and a cross sectional View of the plate alone is shown in Figure 13. The modified target plate 63 is made preferably of plywood or of some strong light weight composition product. The leading edge of the plate is provided with a fairing strip 64 which is bent back over the fin and tacked or riveted thereto. The use of such a fairing decreases the air resistance of the plate and serves to prevent any tendencv of the composite material to split longitudinally under the eiect of air pressure at high speeds as well as bracing the plate to the base structure. The base of the plate is secured in a channel 65 of substantially. the cross section shown in Fig. 13 by rivets S6 which pass through both flanges of the channel and the plate. The widened base G1 of the channel is provided with a plurality of apertures 68 similar to the apertures 30 provided in the Figure 1 modication. A notch 69 has been provided in the plate in opposition to each aperture 68 to allow for the free reception of the hooks 62 which secure the plate to the body. The modified target plate is applied in the same manner as the plate of the Fig. 1 modication, previously discussed.

It is obvious that the manufacture of this latter modification is much simpler than that of the previously described modifications and that a considerable saving of material is effected. As

the target supporting tube is considerably larger than the expansion nozzle of the rocket little if any decrease in efliciency results from surrounding the expanding gases as they leave the nozzle.

Figure 15 shows a modification in the style of front end closure which provides for an electric primer adapted to ignite the rocket charge. The forward end of the motor tubell is provided with a portion of slightly reduced diameter and external threads l0 have been formed thereon. Engaging the threads lll and securing a charge supporting diaphragm in a mannersimilar to that shown in Fig. 1 is a centrally apertured and cuplike cap ll. A tubular member 'l2 closed at one end and externally threaded at the other end is provided with a lock nut 13 and is-passed through the central aperture in the cap into threaded engagement with an ogival nose weight 14. Insulating washers l5 and a bushing 16 of the same material electrically isolate the tubular member and ogival weight from the motor body and cap thereon. The tubular member is preferably provided with a plurality of flash holes 11 which may be conveniently sealed on the inside by a cylinder 18 of paper or other readily frangible or combustible material. The tubular member is substantially lled with an easily ignited charge 19 such as black powder and an electric squib 8|] is surrounded thereby. One of the leads 8l from the squib is electrically connected to the ogival weight 14 and the other lead 82 is connected to the body cap 1|. It will be readily apparent that the connection of a source of electric current between the ogival weight 14 and motor tube 60 will result in ignition of the squib and in communication of the ignition to the main driving charge. Obvious modications will enable such a primer to be used with either of the other types of rocket body.

Figure 14 shows another form of primer unit which may be conveniently utilized to effect the ignition of the driving charge of any of the rockets discussed above. The primer comprises an electric squib or blasting charge igniter 83, which is supported by a disk 84. A container is substantially filled with black powder 86 and is secured to the disk 84 by cementing or other convenient means with the powder 86 surrounding the charge igniter 83. A spacer stick 81 is secured to the disk 84 to located the igniting charge well within the rocket body and a cork or plug 89 is provided on the stick to engage the nozzle and loosely retain the primer assembly in the rocket body. Electrical conductors 88 leading to the charge igniter 83 are secured to the spacer stick and passed through the plug 88 for connection to a battery or other source of current.

Obviously other modications of the invention may be produced which will fall within the bounds of my invention as set forth by the appended claim.

I claim:

In a mobile target of the type comprising a rocket and wing members, the improvement comprising a hollow wing member of substantially triangular cross-section transversely of the rocket axis, a bi-lanceolate member of channel section xedly nested in the base of the wing member to provide aerofoil sections parallel to the rocket axis, a tube surrounding the rocket and having outwardly struck portions, pairs of perforations in the bi-lanceolate member each defining a central web portion and each of said struck portions on the tube being received in one of the pairs of perforations and engaging the said web,

the perimeterof said wing being semi-circular with its diameter coinciding substantially with the rocket axis.

LESLIE A. SKINNER.

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

UNITED STATES PA'IENTS Number Number Number Name Y Date Stokes Aug. 26, 1919 Rogozea. Apr. 13, 1920 Van Deuren Nov. 30, 1920 Tiling Oct. 4, 1932 Stolfa et al Mar. 14, 1933 Holcomb Feb. 8, 1938 Holcomb Mar. 7, 1939 Morgan et a1 July 4, 1939 Prensky Dec. 12, 1939 Anzalone Mar. 23, 1946 FOREIGN PATENTS Country Date Great Britain May 22, 1919

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