US 3357306 A
Description (OCR text may contain errors)
Dec. 12, 1967 C. A. BOYD ETAL.
ACCELERATING PARTICLES TO HIGH VELOCITIES Filed June 29, 1965 INVENTOILS` CHA/M55 A. 907D Y PH/L/P G. LUCKHARDT United States Patent O 3,357,306 ACCELERATING PARTICLES T HIGH VELUCITIES Charles A. Boyd and Philip G. Luckhardt, West Chester,
Pa., assignors to Aeroprojects Incorporated, West Chester, Pa., a corporation of Pennsylvania Filed June 29, 1965, Ser. No. 468,006 Claims. (Cl. 89-8) This invention relates to apparatus invented for accelerating particles or projectiles so that they may attain high velocities.
The present invention permits relatively large projectiles of known mass to be directed toward a target at high velocities. In this manner, laboratory studies for impact effects on various structures and materials are facilitated. Accordingly, meteor impact problems, missile nose cone design, inter alia, maybe studied under a condition simulating outer space.
One of the major obstacles to such studies in the laboratory is to provide a means for creating sufficiently high velocities for relatively large projectiles. The present invention overcomes this obstacle by sequentially accelerating a moving projectile. The sequential acceleration is preferably accomplished by sequentially detonating explosive shaped charges along the path of the projectile so that the explosive force of each shape charged further accelerates'the projectile.
It is an object of the present invention to provide a novel apparatus foraccelerating projectiles.
It is another object of the present invention to provide a novel method of accelerating projectiles.
It is another object of the present invention to provide a novel method and apparatus for accelerating projectiles at very high velocities to facilitate laboratory studies of impact problems and the like.
It is another object of the present invention to provide a method and apparatus for simulating outer space Conditions for impact studies of meteorites and the like.
Other objects will appear hereinafter.
For the purpose of illustrating the invention, there are shown in the drawings forms which are presently preferred; it being understood, however, that this invention is not limited to the precise arrangements and instrumentalities shown.
FIGURE l is a diagrammatic illustration of the present invention shown in section.
FIGURE 2 is a sectional view taken along the line 2 2 in FIGURE 1.
FIGURE 3 is a view similar to FIGURE 2 but illustrating another embodiment.
Referring to the drawing in detail, wherein like numerals indicate like elements, there is shown in FIGURE 1 an apparatus designated generally as 10.
The apparatus includes a housing 12 which may be cylindrical as shown more clearly in FIGURE 2. The housing 12 is provided with end walls 14 and 16. The
interior of the housing 12 is provided with partitions 18,.
22 and 26. End wall 14 and partition 18 cooperate with the housing 12 to define a chamber 20.
Partitions 18 and 22 cooperate with the housing 12 to define a chamber 24. Partitions 22 and 26 cooperate with the housing 12 to define a chamber 28. Partition 26 and end wall 16 cooperate with the housing 12 to form a chamber 30. The chambers 20, 24, 28 and 30 are serially disposed. If desired, a thin walled tube 32 made from a material such as aluminum may be coaxially disposed within the housing 12 and extending between an inlet in the wall 14 to an outlet in the wall 16. Any suitable means such as nuts and bolts may be used to retain the tube 32 in a predetermined disposition.
The barrel 34 of a gun, not shown, extends through the 3,357,306 Patented Dec. l2, 1967 inlet in end wall 14 in line with the tube 32. The gun is preferably a pneumatic gun for firing projectile 36 through the tube 32 toward the target 38. Target 38 may be supported externally of the housing 12 in any convenient manner or may be completely disconnected from the accelerator. For some laboratory studies, the target 38 may be supported by a tubular extension 39 having a chamber 41 therein. Chamber 41 may be evacuated by means of conduit 43 as will be made clear hereinafter.
Within chamber 20, there is supported an annular shaped charge 40 having a detonator 42. A means is provided for sensing the presence of the projectile 36. This may be simply accomplished by providing suitable apertures in opposite sides of the tube 32, and utilizing an optical sensing means such as photoelectrc cells 44 and 46. As the projectile 36 interrupts the beam between the cells 44 and 46, current will be supplied to the detonators 42 to detonate the same. The cells 44 and 46 are spaced from the shaped charge 44 by a distance so that the shaped charge 40 will be detonated at a time interval whereby its explosive force will accelerate propulsion of the projectile 36.
The shaped charge 40 may be supported in any convenient manner such as by brackets 48. Within chamber 24, there is provided comparable photoelectrc cells, shaped charge and detonator provided with primed` numerals. The photoelectrc cells 44 and 46 are spaced slightly further from the shaped charge 40. The spacing takes into consideration that the projectile will be moving faster when passing through chamber 24. In chamber 28, there are provided corresponding elements with double primed numerals. The cells 44 and 46" are spaced further from the shaped charge. 40 as compared with the corresponding elements in chamber 24.
The various chambers within the housing 12 as Well as chamber 41 are preferably evacuated for meteoroid simulation studies, but need not be evacuated for other studies. This may be accomplished by a manifold 50. Chamber 20 and manifold 50 are interconnected by conduit 52. Chamber 24 and manifold 50 are interconnected by conduit 54. Chamber 28 and manifold 50 are interconnected by conduit 56. Chamber 30 and manifold 50 are interconnected by conduit not shown. Chamber 41 and manifold 50 are interconnected by conduit 43. A vacuum pump 58 may be provided with its inlet side communicating with the manifold 50.
The operation of the apparatus 10 is as follows:
A projectile 36 of large mass is fired through barrel 34 into the tube 32. For meteorite impact studies, a large mass would be one gram. As the projectile 36 interrupts the light beam between cells 44 and 46', the detonator 42 is detonated thereby exploding the shaped charge 40. The explosive force of shaped charge 40 bursts the portion of tube 32 immediately adjacent thereto and accelerates the speed of the projectile 36. As the projectile 36 enters the chambers 24, it will interrupt the light beam between cells 44 and 46'. As a result thereof, the shaped charge 40 will be detonated bydetonator 42. This explosive force will likewise accelerate the speed of the projectile 36. The above sequence will be repeated throughout the length of the housing 12, as desired, so that the explosive force of each shaped charge will sequentially increase the speed of the projectile so that speeds of at least 10,000 meters per second may be attained when the projectile contacts the target 38. If desired, the pressure on opposite sides of the target may be equal or substantially equal by extending the length of the chamber 41.
Doors not shown are provided in the housing 12 so that access may be had to each of the chambers therein to facilitate replacement of the shaped charge and detonators. After each firing the tube 32 will be replaced. It will be appreciated that the drawing is only schematic in that reinforced ribbing, and a rigid support to counteract the explosive force from the shaped charges, etc. will be provided. For certain testing operations, the thin walled aluminum guide tube 32 may be eliminated. For purposes of illsutration, the projectile is illustrated as having a spherical shape. It will be appreciated that other contours may be provided for the projectile 36. It will be appreciated by those skilled in the ar-t that the super high velocity gas jet formed by the explosion of the shaped charges gives the projectile 36 a velocity boost by momentum transfer.
In FIGURE 3 there is illustrated an alternate arrangement wherein a cylindrical charge 60 may be substituted for the shaped charges identified above. When using cylindrical charges, the projectile 36' should have a conical tail section providing a reaction surface 6,2. The force or momentum of the explosion products imploding inwardly in a radial direction from charge 60 immediately destroys the juxtaposed portion of tube 32 and acts on surface 62 .to provide a force component thereon to propel projectile 36' forwardly in the same manner as described above. In this way it will be seen that, theoretically at least, the terminal velocity of the projectile can exceed the particle rvelocity of the imploding gas. It will be noted that the .charges in FIGURES l-3 are annular.
The .present invention may be embodied in other specific forms without departing from the spirit or essential attributes thereof and, accordingly, reference should be made to the appended claims, rather than to the foregoing speciiication as indicating the scope of the invention.
1. Apparatus for accelerating projectiles to high velocities comprising a housing, means for evacuating said housing, a plurality of aligned annular explosive charges vin said housing, said housing having an inlet and an outlet aligned with said charges, sensing means for sequentially firing each charge whereby each charge will accelerate the speed of a projectile passing through said housing and partitions dividing said housing into separate chambers, means for supporting the charges in said chambers, and each charge having its own sensing means coupled thereto.
2. Apparatus in accordance with claim 1 including a thin walled guide tube extending through said partitions between said inlet and said outlet and through which the projectile will be propelled, with the rcharges being annularly disposed around said tube..
3. Apparatus in accordance with claim 1 wherein said sensing means is an optical sensing means.
4. Apparatus in accordance with claim 1 including a target supported by the housing, said housing having a chamber between the target land the charge closest to the target, said last mentioned chamber being evacuated by said evacuating means.
5. Apparatus in accordance with claim 1 wherein said sensing means includes an optical sensing means associated with each of the charges-which are shaped charges, the distance -between the shaped charges and their respective optical sensing means being progressively farther from each other in a direction extending from the inlet toward the outlet, whereby the distance ,betweenithe sensing means and .shaped charge adjacent the inlet is less than the corresponding distance between the sensing means and shaped charge adjacent the outlet.
References Cited UNITED STATES PATENTS 3,031,933 5/ 1962 Kern et al. 89-8 3,054,329 9/ 1962 Willig 89.-8 X 3,065,695 11/ 1962 Jarrett 102-24 3,132,562 5/ 1964 Frevel `89-8 X v3,215,074 ll/ 1965 Robinson et al. 102-,-24
SAMUEL W. ENGLE, Prima-:jy Examiner.