US 3625152 A
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United States Patent Inventors Appl. No. Filed Patented Assignee lMPACT-ACTUATED PROJECTILE FUZE 21 Claims, 3 Drawing Figs.
US. Cl 102/73, 102/58, 102/7611, 102/85 Int. Cl F42: 1/10, F42c 9/00 Field of Search 102/58, 38, 70, 73, 75, 85. 76
 References Cited UNITED STATES PATENTS 2,627.160 2/1953 MacDonald 102/70 X 3.345.945 10/1967 Quinlan et a1. 102/38 3,353,488 11/1967 Stadler eta] 102/73 Primary Examiner-Samuel W. Engle Attorney-Allen J. Jafl'e ABSTRACT: A projectile housing. A body of pyrotechnic material in the housing. A fuze container fixed to the base end of the housing. A burning fuze material in the fuze container, the container fabricated of a material that looses its structural integrity in response to the heat of the fuze flame front, whereby upon impact of the projectile that container separates exposing the burning fuze to the body of pyrotechnic material.
PATENTEUUEB nan 3,525,152
sum 2 or 2 INVENTOR RICHARD E. REINNAGEL CLAYTON J. SCHNE!DER,JR.
ATTOR NEY IMPACT-ACTUATED PROJECTILE FUZE BACKGROUND OF THE INVENTION The present invention relates to fuzes, and more particularly to those which are armed upon firing and actuated upon impact.
Fuzes have been used which prevent immediately actuation of the main charge by the provision of a fixed delay period or by the provision for impact actuation or both. The systems utilizing impact actuation usually incorporate some form of mechanical latching or detaining means which is released upon impact of the projectile. Such mechanical structure suffers from several serious drawbacks. Mechanical systems are usually costly, large and may be subject to premature actuation due to rough handling.
SUMMARY OF THE INVENTION The foregoing as well as other disadvantages of prior devices are overcome according to the principles of the present invention which provides an impact actuated fuze which is inexpensive, safe and compact.
Basically, the present invention provides a pyrotechnic delay material packed in a tube or container which is rigidly affixed to the base end of the projectile. Upon suitable ignition of the delay material, the mechanical properties of the tube are effectively destroyed, thus permitting the burning pyrotechnic to travel in a direction which makes contact with the main charge upon impact.
According to one aspect of the invention, suitable for stabilized projectiles, the burning pyrotechnic delay material travels forward toward the nose end of the projectile upon impact.
According to a second aspect of the invention, suitable for nonstabilized projectiles such as grenades, the burning pyrotechnic delay material may travel radially outward through slots in a supporting member.
BRIEF DESCRIPTION OF THE DRAWINGS For a fuller understanding of the present invention reference should now be had to the following detailed description of the same taken in conjunction with the accompanying drawings, wherein:
FIG. I is a longitudinal sectional view of a projectile embodying the principles of the present invention,
FIG. 2 is a fragmentary sectional view of a second embodiment, and
FIG. 3 is a schematic plan representation ofa third embodimCI'II.
DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring now to the drawings and, more particularly, to FIG. I, the projectile housing is generally depicted by the numeral I and is defined by a generally cylindral central section 12 to which is suitably affixed a cup-shaped forward end or ogive l4 and a base end plug, 16. Forward end 14 has a conventional vent opening 15 therethrough. The housing may be fabricated of any suitable material such as an aluminum alloy or steel. The base end plug I6 has an inwardly stepped ledge I8 terminating in a central opening 20. Passing through opening and extending into the projectile housing is a tubular insulating and supporting sleeve 22, which may be fabricated of any suitable material such as plastic. Sleeve 22 is affixed to the plug I6 at the ledge I8 by means of an integral flange 24.
A cylindrical, tubular fuze container 26 is received in sleeve 22 and is suitably affixed thereto, as by cement or the like, adjacent flange 24. In this manner the fuze container is fixed to the base end of the projectile housing.
A body of fusing material 28 is located within container 26. This material might typically comprise a slag and/or gas producing pyrotechnic such as 3 percent boron and 97 percent barium chromate mixture. A first fire mix 30 ofa suitable pressed priming material such as red lead and silicon closes the base end of container 26 and passes through an opening 32 in flange 24 to the exterior of the projectile housing for ignition in the conventional manner. A similar output mix 34 closes the opposite or forward end of container 26.
A main charge 36 substantially fills the interior of the housing [0 except for a central bore 38 in which is located the fusing material 28, its container 26 and supporting sleeve 22. The main charge might comprise any suitable type of burning pyrotechnic such as red smoke, for example.
The fuze container 26 is fabricated of a material which is sufficiently weakened by the traveling flame front in the fusing material 28 such that upon impact of the forward end of the projectile the forward portions ofthe container separates from the rearward portion thereof. Various materials exhibiting such a weakness, may be chosen. For example, a thin-walled aluminum tube having a thickness of about 0.012 inches becomes molten adjacent the flame front. Alternatively. a phenolic or plastic tube, would become pyrolized adjacent the flame front. In either case, the flame front causes the material of the container adjacent thereto to loose its structural integrity whereby upon impact separation occurs.
The operation of the device according to the present invention should be apparent from the foregoing description. Thus, when the projectile is fired by conventional means (not illus trated) the first fire mix 30 receives ignition (from propellant in a cartridge case, for example) and burns through the opening 32 into the fusing material 28 which is thereby ignited generating a flame front which travels towards the forward end of the projectile. The heat of the flame front is sufficient to melt, pyrolize or otherwise weaken the structural integrity of the fuse container. Upon impact with a target, the container 26 separates at the weakened spot and the unburned portion of the fusing material together with the flame front and considerable quantities of slag from the burned portion of the fus ing material travel beyond the sleeve 22 into the main charge 36 and ignite the same. In the event that an insufficient impact fails to part the container or if impact does not occur in a specified time, say 6 seconds, the fusing material continues to burn until it ignites the output mix 34 which sprays flame and slag into main charge to ignite the same. The insulating sleeve 22 prevents the heat of combustion of the burning delay mix 28 from igniting the main charge 36 prior to impact or before the end of the specified time period.
Although the foregoing description related. by way ofexample, to the ignition of a pyrotechnic material by means of a traveling ignition source, it is obvious that a pin or stab could be placed on the forward end of the fuze which would function to initiate a primer at the forward end of the projectile. In this manner a detonation output can be obtained.
The forms of the invention shown in FIGS. 2 and 3 relate to projectiles that are not stabilized in flight such as hand-thrown grenades or the like. Here there is no guarantee that the projectile will impact in a nose-forward position.
The FIG. 2 embodiment is similar to the previously described FIG. I embodiment, except that the insulating and supporting sleeve, designated as 22; has a plurality of longitudinally extending slots 23'. Upon impact at any orientation, the molten or pyrolized portions of fuse container 26 together with the slag and flame from the fusing material 28 splashes through the slots 23' to trigger the ignition of the main charge.
Alternatively as shown in FIG. 3, a plurality of fuzes, each similar to the fuze elements 22, 26, 28, 30 and 34 of the FIG. I embodiment, could be joined together at hub I00, which structure would then be located in a spherical projectile housing embedded within a main charge (not illustrated). In this manner one of the fuzes of the set would be subject to set-forward forces regardless of the angle of impact of the device. The fuzes are shown in a common plane for ease in presentation only. It is preferable that various planes be occupied by separate fuzes.
Although various embodiments of the present invention have been described by way of example, other forms thereof will be obvious to those skilled in the art.
1. A projectile, comprising:
a. a housing having a forward end and a base end.
b. a main charge of ignitable material in said housing,
c. a container fixed to said housing,
d. a fusing material located within said container and normally separated from contact with said main charge,
e. means for igniting said fusing material prior to impact of the projectile thereby generating a traveling flame front, and
f. said container being fabricated of a material which is sufficiently weakened by said flame front such that upon impact of said housing a portion of said container separates from the remainder thereof whereupon the separated portion and the fusing material comes into contact with said main charge.
2. The projectile according to claim I, wherein said container is fixed to said base end of said housing.
3. The projectile according to claim I, wherein said container is substantially tubular.
4. The projectile according to claim 3, further comprising a tubular insulating and support sleeve fixed to said housing and in surrounding spaced relation to said container.
5. The projectile according to claim 4, wherein said sleeve contains a plurality of longitudinally extending slots.
6. The projectile according to claim I, further comprising additional containers each mutually interconnected with said first mentioned container by means ofa central hub.
7. The projectile according to claim I, wherein:
g. said main charge substantially fills said housing, and has a throughbore extending therethrough and wherein,
h. said container is substantially tubular and located within said throughbore.
8. The projectile according to claim 7 wherein said container is affixed to the base end of said housing.
9. The projectile according to claim 8, further comprising a sleeve extending from said base end into said throughbore in surrounding relation to said container.
10. The projectile according to claim 9, wherein said sleeve has a plurality of longitudinal slots.
II. A projectile comprising:
a. a housing having a forward end and a base end,
b. a main charge of ignitable material located in said housc. a container in said housing fixed to said base end,
d. a fusing material located within said container and normally separated from said main charge,
e. means for igniting said fusing material prior to impact of the projectile to generate a flame front which travels in a direction from said base end to said forward end of said housing, and
f. said container being fabricated of a material which is sufficiently weakened by said flame front such that upon impact of said forward end of said housing the forward portion of said container separates from the base portion thereof and travels into said main charge.
12. The apparatus according to claim ll, wherein;
g. said container is substantially tubular and there is further provided;
h. a sleeve surrounding said container, and
i. first fire and output mixes located respectively at the base end and forward end of said container.
13. The apparatus according to claim [2, wherein said container is located in a throughbore in said main charge.
14. A projectile fuze, comprising;
a. a container b. a body of fusing material located in said container, c. means for igniting said fusing material prior to impact of the projectile for generating a traveling flame front, and d. said container being fabricated of a material which is sufficiently weakened by said flame from such tat upon impact a portion of said container separates from the remainder thereof.
15. The fuze according to claim 14, further comprising:
e. insulating means in surrounding relation to said container.
16. The fuze according to claim 14, further comprising; e. a first fire mix at one end of said container, and
f. an output mix at the other end of said container.
17. The fuze according to claim 14, wherein;
e. said container is substantially tubular.
18. The fuze according to claim 17, further comprising;
f. a tubular insulating sleeve in surrounding spaced relation to said container.
19. The fuze according to claim l8, wherein;
g. said sleeve contains a plurality of longitudinally extending slots.
20. The fuze according to claim 19, further comprising;
h. a first fire mix at one end of said container, and
i. an output mix at the other end ofsaid container.
21. The fuze according to claim l4, further comprising;
e. additional containers, each mutually interconnected with said first mentioned container by means ofa central hub.
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