|Publication number||US3414218 A|
|Publication date||Dec 3, 1968|
|Filing date||Jun 22, 1967|
|Priority date||Jun 22, 1967|
|Publication number||US 3414218 A, US 3414218A, US-A-3414218, US3414218 A, US3414218A|
|Inventors||Clarence J Russnak|
|Original Assignee||Motorola Inc|
|Export Citation||BiBTeX, EndNote, RefMan|
|Patent Citations (10), Referenced by (2), Classifications (7)|
|External Links: USPTO, USPTO Assignment, Espacenet|
Dec. 3, 1968 c. J. RUSSNAK AIR DROPPABLE APPARATUS Filed June 22, 1967 cum/c5 J RUSS/MK United States Patent 3,414,218 AIR DROPPABLE APPARATUS Clarence J. Russnak, Scottsdale, Ariz., assignor to M0- torola, Inc, Franklin Park, IlL, a corporation of Illinois Filed June 22, 1967, Ser. No. 648,080 7 Claims. (Cl. 244138) ABSTRACT OF THE DISCLOSURE A cylindrical housing with an X-shaped spear or spike with a conical section adjacent one end of the housing and a set of stabilizing fins at the opposite or upper end which have a tapered upper edge for accommodating rotochute blades when the blades are just beginning to rotate. An antenna extends coaxially upwardlly past the rotochute. Provisions are made for attaching a parachute in lieu of using a rotochute.
Background of the invention The present invention relates generally to air droppable apparatus and, more particularly, to such apparatus adapted to remain in an upright position after landing.
There have been several forms of air d-roppable apparatus most of which are suitable primarily for high altitude air drops or when used at low altitudes for low air speeds. Such prior devices include devices with an elongated round spike or spear on one end for penetrating the ground. Such spikes were good for high altitude drops but do not penetrate sufiicient to keep the apparatus in an upright position when dropped at low altitudes. Further, when dropped from high speed aircraft such apparatus have a tendency to roll over and assume a horizontal position.
When air droppable apparatus is used to establish a radio communication link or a radio beacon, it is quite important that the antenna in the apparatus be in an upright position. Air craft height and speed are relative for a successful drop; the greater the speed, the higher the aircraft must be for a successful drop. Also, such round points do not penetrate paved surfaces sufficiently for successful implantation. Such devices have used rotochutes or parachutes for use as air brake for rate of descent control. I
When air drop velocity is high there is a substantial impact upon hitting the ground. When air dropped apparatus is carrying fragile electronic apparatus, for example, means have been provided for protecting the apparatus from shock. Such additional means, including hydraulic shock absorbers, and weight to the apparatus and, therefore, reduce the cargo carrying capacity.
Generally, stabilizing fins have been added to the apparatus to keep it from unduly spinning as it descends. When using such stabilizing fins with a rotochute, for example, such fins can interfere with the operation of the rotochute or the fins can be placed midway of the apparatus housing which adds certain undesirable instabilities to the descent.
Summary of the invention It is an object of the present invention to provide a lightweight air droppable apparatus which can land in an upstanding manner from low altitude high speed release.
3,414,218 Patented Dec. 3, 1968 ice the features of having a cylindrical housing with an X or star-shaped ribbed spike or spear on one end portion and a descent air velocity limiting means on the other or upper end portion, such as a rotochute or parachute. An antenna may extend coaxially through the rotochute. The starshaped spear has two lportions; the first or lower portion has a very small taper in the outwardly projecting ribs, for example, the lower one-third length of the spear, while the latter two-thirds or upper portion has a much greater taper in the ribs. Also, immediately adjacent to the housing and the portion with the greater ta pered ribs there is provided a conical projection for limiting the penetration when it lands in sand. The spear is in threaded engagement with the housing for facilitating removal and as sembly.
The upper portion of the housing includes a rotochute with stabilizing fins extending between the rotochute blades when in an unactuated position. The upper edges of the fins are tapered. As the apparatus begins to drop, the rotochute blades move outwardly without rotation. Before the rotochute blades begin to rotate, the blades have reached a position above the tapered upper edge of the stabilizing fins and, therefore, clear the fins upon the onset of rotation. This arrangement permits the fins to be at a maximum rearward or upper position on the housing for maximum stability of descent. The device center of gravity is preferably below the axial center of the housing and the load is preferably balanced about the axial center line of the housing.
The drawing FIG. 1 is a side elevational view of one apparatus incorporating teachings of the present invention.
FIG. 2 is a partial exploded view of the front end portion of the FIG. 1 apparatus showing how the X-shaped point attaches to the cylindrical housing.
FIG. 3 is a front elevational view of the FIG. 1 apparatus showing the outwardly projecting ribs of the front end spear and the stabilizing fins.
Description of the illustrative embodiment Like numbers and characters indicate like parts and structural features in the various views. The illustrative apparatus includes cylindrical housing 10 for containing electronic apparatus 16 or other air cargo. Housing 10 has lower end portion 11 and upper end portion 12 indicating the upper and lower ends during descent. Air drop velocity limiting means, such as a rotochute 13, is attached to upper end portion 12. It is understood that a parachute may be substituted for rotochute 13 as by threading the cords of a parachute through the apertures in collar 14. Collar 14 is threadingly engaged to the upper end portion 12 and may be used to tightly fit against cargo 16 inside housing 10. In this embodiment cargo 16 is a radio device housing upwardly projecting antenna 17. Novel ribbed spear 15 is threadingly engaged to lower end portion 11 and is designed to penetrate hard pavement, such as asphalt, as well as providing good resistance to penetration of soft sand such that the apparatus can remain in an upstanding position when landing on either extreme surface types with minimum landing shock. When housing 10 is upright, antenna 17 extending axially outwardly from end portion 12 is in an upright preferred operating position. A set of novel stabilizing fins 20, 21, 22, and 23 are fixedly attached to the upper end portion 12 as shown. Housing 10 has central axis 18 around which all weight is symmetrically distributed. The center of gravity 19 is preferably closer to end portion 11 than portion 12 to make the descent more stable and ensure that spear 15 is always pointed downward after release from an aircraft (not shown).
Spear 15 is especially designed for high speed low altitude air drops, as will become apparent. Spear 15 includes a plurality of outwa ndly projecting ribs 30, 31, 32, and 33 symmetrically disposed about axis 18. The lower one-sixth portion 34 of spear 15 has a very small taper such as A1" in 3" in the ribs from the extreme point for providing ease of penetration into hard surfaces, such as asphalt. This lower portion, which may be up about /3 the length of the spear, ensures that air dropped apparatus can be in an upstanding position when landing on a hard surface. The ribs of upper five-sixths portion 35 of spear 15 have a greater taper such as twice the lower portion and act as a cushion when the apparatus is penetrating into the ground. The greater taper also adds to the stability of the apparatus after it has landed. Further, spear 15 is provided with depending cone 36 symmetrically formed about axis 18 and extending, for example, along the upper one-third portion or less, as best seen in FIG. 1. Cone 36 is adapted to act as a brake when the air dropped apparatus lands in a soft surface such as sand or swampy ground. It also serves as an additional cushion as spear 15 is penetrating the ground.
The terms high and low altitudes, as used herein, refer to the relative speed at release with respect to actual altitude. As an example, a high speed low altitude drop using an air droppable apparatus such as described was repeatedly successfully dropped at an altitude of 350 feet at an air speed of 150 knots. A successful drop means the FIG. 1 illustrated apparatus remained in an upstanding position with spear 15 penetrating ground surface. At higher altitudes, aircraft speeds can be proportionately increased. The above cited figures represent a high speed low altitude drop. Such air drops were successful even when the portion 12 was pointed downward at release.
Referring now more particularly to FIG. 2, there is illustrated in an exploded view the connection between spear 15, housing 10, and electronic apparatus 16. Spear 15 has axially extending, externally threaded projection 40 for receiving the inner coarse threads 41 of collar 42 and being in threaded engagement with housing 10. Collar 42 has a set of fine external threads 43 to engage fine internal thread 44 of the housing 10. It has been found that the use of the collar 42 as described provides a facile connection between spear 15 and housing and permits air cargo 16 to be securely directed against spear such that the cushioning effect of spear 15 can be utilized.
The upper portion of the apparatus will be now described in more detail. The fins 20, 21, 22, and 23 are fixedly secured to the housing 10 as by a pair of annular straps 49, as shown. The fins are preferably as far upward along portion 12 as possible to ensure stable descent. To this end, the fins are all tapered at the upper edges as at 51 to accommodate the blades of rotochute assembly 13. The taper 51 is designed such that when the rotochute 13 blades have opened outwardly from the air passing by and are just beginning to rotate, the blades clear the fin inwardly upper tapered edges 51. Rotochute 13 is rotatably secured to the base of antenna 17 by clamp 50.
The entire apparatus can easily be assembled by first affixing spear 15 to housing 10 and then inserting air cargo 16 with collar 42 attached and threadingly engaging it into projection 40. Then collar 14 may be threadingly engaged in the upper end portion 12 for holding cargo 16 securely inside housing 10. It should be noted that antenna 17 extends coaxially through collar 14. Then annular straps 49 are secured to housing 10 in a clamping manner. Then rotochute 13 is securely attached to the base of antenna 17 by clamp 50. When a parachute is used with the apparatus, rotochute 13 is not included in the assembly and a parachute is affixed to collar 14 through the illustrated apertures 14A.
1. Air droppable apparatus, including in combination,
a cylindrical housing with upper and lower end portions and having an axis along its length central of the cylinder,
an axially extending spear on said lower end portion symmetrical about said axis and having a plurality of radially outwardly extending ribs symmetrically disposed about said axis and tapered from a maximum radial dimension immediately adjacent said lower end portion to a minimum radial dimension at an extreme point disposed axially from said lower end portion away from said upper end portion, said ribs tapering from said extreme point at a relatively small angle up to about between one-sixth and onethird the length of said spear and at a much greater angle between said lower end portion and said small angle taper of said spear, said ribs having platelike radial surfaces,
air velocity limiting means on said upper end portion,
a conical projection extending from said lower end portion along said axially extending spear filling the space between adjacent radially extending ribs and tapering to a point not more than one-third the distance from said lower end portion toward said extreme point along said axis, and
a plurality radially outwardly extending stabilizing fins symmetrically disposed about said axis on said upper end portion.
2. The apparatus of claim 1 wherein said air velocity limiting means comprises rotochute means secured to said upper end portion with rotatable blades when in an unactuated position lying between said radially extending fins, each fin having an upper end portion and a radially outward portion and a tapered portion extending from said upper end portion radially outwardly toward said radially outward portion such as to form an upper edge including a tapered portion forming an acute angle with said cylinder with the apex of the acute angle pointing toward said upper end portion.
3. The apparatus of claim 1 wherein said small angle taper is one-eighth inch in three inches and extends for one-sixth the length of said spear.
4. The apparatus of claim 1 wherein said spear has an upwardly extending projection with outer threads, a collar threadingly engaging said outer threads, and
the collar further including internal and external threads with the external threads engaging internal threads on said housing.
5. The apparatus of claim 4 wherein said collar internal threads are coarser than said collar external threads.
6. The apparatus of claim 1 further including a collar threadingly engaged to the upper end portion of said housing and having apertures for receiving a parachute and operative to securely hold air cargo within said housing.
7. The apparatus of claim 1 wherein there are four radially outwardly extending stabilizing fins and four outwardly extending ribs with the fins and the ribs each forming an X symmetrically about said axis.
References Cited UNITED STATES PATENTS 3,288,402 11/1966 Icenbice et a1. 244-138 417,433 12/1889 Lorenz 43-6 1,250,178 12/1917 Hover 102-3 X 2,417,980 3/1947 Goss 102-2 2,440,291 4/1948 Pitcairn 244-138 2,978,211 4/1961 Wannlund et al. 244-138 3,013,493 12/1961 Fletcher 102-356 3,016,217 1/1962 Polleys et al. 244-138 3,098,445 7/1963 Jackson 102-49 FOREIGN PATENTS 82,073 8/1919 Switzerland.
MILTON BUCHLER, Primary Examiner. RICHARD A. DORNON, Assistant Examiner.
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|U.S. Classification||244/138.00R, 473/585, 102/385, 473/586|