US2342096A - Illuminating projectile - Google Patents

Description

2 Sheets-Sheet 1 Feb-15, 1944. 1 J. ZIMMERMAN ILLUMINATING PROJEGTILE Filed Aug. 21, 1941 Feb 15, 1944- l.. J. ZIMMERMAN 2,342,096

ILLUMINAT ING PROJECTILE Filed Aug. 2l, 1941 2 Sheets-Sheet 2 ATTO NEYS Patented Feb. i5, ili

ILLUMINATING PROJECTILE Louis J. Zimmerman, Jackson Heights, N. Y.

Application August 21, 1941, Serial No. 407,695

3 Claims. (Cl. 102-35) This invention relates to an illuminating projectile.

During the World War a projectile was developed for the United States Government which could be fired from high-powered guns and which would travel substantially the same distance as an explosive shell of the same size. At a given point in the trajectory a sustaining parachute and a receptacle containing an illuminant were ejected from the shell body by an explosive charge which was detonated through themedium of a time fuse and which additionally ignited the illuminant.

The illuminant receptacle was connected to the suspension lines of the parachute and the burning of the illuminant illuminated objects below as the sustaining parachute with the ignited and suspended illuminant descended. However in these shells the arrangement of the parachute and the illuminant was such that the illuminating was done only in a downward direction so that scarcely any, if any, light was cast upwardly.

With the increase of aeroplane activity in the present war, especially in bombing and reconnoitering raids over foreign territory, it is ofY course desirable to illuminate the enemy aeroplane and yet maintain an area of darkness in which the defending aeroplanes may cruise and from which they may attack the enemy aeroplanes without beiner detected.

I have in mind the laying down, at night, of a barrage of illuminating shells some distance below the enemy aeroplanes so that the under sides of these aeroplanes will be illuminated and so that below the barrage area a dark area will exist in which the defending planes may cruise and from which they may attack the enemy planes, which will be brightly outlined against the darkness above, and yet will themselves be invisible to the enemy.

With this principal object in view I have devised a sustaining parachute and an illuminant which are so constructed, related and assembled that an ignited illuminant will cast its light upwardly upon the under sides of the enemy aeroplanes and will cast substantially no light below.

I contemplate embodying this device in the World War shell case to which I have above referred, and which became known as the star shell, or in a projectile that may be red from a lower powered gun, such as a mortar or indeed from a Very pistol, depending upon the range desired.

In the drawings I have illustrated a device as embodied in a long range projectile such as a star shell, capable of being iired from the highpowered gun, wherein:

Figure 1 is a. longitudinal sectional view of an illuminating shell built according to an embodiment of the invention;

Figure 2 is a section on line 2-2 of Figure 1, looking in the direction of the arrows;

Figure 3 is a section on line 3-3 of Figure 1;

Figure 4 is a section on line ll-li of Figure l;

Figure 5 is a section on line 5 5 of Figure l;

Figure 6 isa section on line 6--6 of Figure 1;

Figure '7 is an elevation of the parachute with its supported illuminant in operation;

Figure 8 is an enlarged detail of the illuminant container showing the manner in which it is attached to the parachute canopy and showing the illuminant sustaining ribs; and y Figure 9 is an enlarged view of a portion of the canopy.

The embodiment of the invention illustrated in Figures 7 and 8 of the drawings includes a canopy l which may be made somewhat similar to the present standard Army and Navy canopies by joining together a number of panels, the number being preferably sufficient to give to the canopy, when inflated, a parabolic form.

Suspension lines 2 are connected to the skirt of the canopy at .the junction of the adjacent panels and extend to and are connected witha weight 3 of suiiicient magnitudel tostabilize the c-anopy and yet not cause a too rapid descent.

In view of the fact that the location and construction of the illuminant container which later will be described makes it quite impossible to normally vent the canopy, vents 4 may be formed in the canopy some distance removed from its apex so that the oscillation of the canopy during its descent will be minimized.

In order that the area above the canopy and any objects, such as aeroplanes, lying within that area may be illuminated, I have provided the canopy with a receptacle containing the illuminant. This receptacle of course may be attached at the apex of the canopy in many dilerent ways, but I have illustrated a form which will admirably serve during use and still adapt itself to commercial manufacture.

A cup-shaped-holder 5 for the illuminant receptacle is secured to the canopy I at its peak in any suitable manner as, for instance, by rivets 6 which attach the cup-shaped holder to the canopy and to a reinforcing plate 1 which backs un the canopy on the side opposite to that on which the holder is located. This cup-shaped hol-der is provided with a rib which is Vadapted to interengage with a complemental channel S in the illuminant receptacle I il.

Of course the holder 5, the plate 'I and the receptacle Iil may be made of thin light material, such as plastic, aluminum or aluminum alloys. The illuminant container III encloses an illuminant II which may be compacted in the Acontainer and reinforced to prevent undue disintegration by a coil I2 which with the flange I3 will prevent the illuminant from accidentally mving as a body from the receptacle.

The illuminant composition may be of any of the well known compositions, such, for instance, as those that have already been used in the star shells referred to, and the coil I2 may be of a soft or pliable metal, such as copper, which can be compressed with the plastic mass when the latter is molded into the nished shape of .the illuminant.

By having the illuminant receptacle separable from the holder 5 the receptacles may be manufactured and packed before being snapped into place on the canopy, which will facilitate 4manufacture.

Of course during burning of the illuminant; undoubtedly particles of molten illuminant will strike the canopy and I therefore contemplate Iusing a reproof material which will prevent the burning of the canopy during the burning life of the illuminant in the receptacle III.

The icanopy must, on the other hand, be of some soft material which will facilitate packing and inflation, but as there are many such materials on Vthe market it seems unnecessary to specify any particular reproof materials as the material to be used may to a greatextent be a matter of choice.

Probably the air pressure within the canopy will be suilcient to sustain the weight of the illuminant and its associated parts against a depression of the peak of the canopy. On the other hand it may be that a degree of additional support will be necessary and therefore I contemplate in one form of the invention the inclusion of sustaining ribs. These ribs I3 may be made of rubber and secured to the bottom plate 1 and to the canopy along each or certain of the seams between the panels by the ordinary zigzag stitching I4, or they may actually be incorporated in the seams of the panels just as suspension lines are now so incorporated in life saving parachutes.

Adjacent the illuminant these ribs should be slightly enlarged as I have illustrated in the drawings, and then may taper off toward the skirt of the canopy. Of course with these ribs incorporated any tendency of the illuminant and its associated parts tov move downwardly relative to the canopy will be resisted by the p-ressure of the air within the canopy along the entire surface of the canopy from the peak to the skirt, because of the attachment of the ribs to the canopy. Indeed this will be true to a lesser extent even without the ribs.

These reinforcing ribs I3 must of course be of quite a pliable rubber since they must be folded with the canopy to be packed' in the shellV casing, but .they need not b-e of a veryY rigid rubber because their rigidity when unfolded is enhanced by their attachment to the canopy by the zigzag stitching.

Other forms of reinforcement may be used, but it is thought unnecessary to illustrate all such forms as the most eicacious form will probably develop empirically.

The suspension lines of the sustaining parachute I may be brought together into a single line,.as shown in Figure 7 of the drawings, and, indeed, as shown in the Bergman Patent 1,305,187 of May 27, 1919, and in this single line graduated smaller parachutes I5 may be incorporated which will tend to materially retard the travel of the illuminant body as it is ejected from the shell casing and thus lessen the strain of arresting this travel on the sustaining parachute I.

I have illustrated this illuminating parachute as incorporated in a standard star shell casing which bears a marked similarity to that in the Bergman patent above referred to.

Describing now this assembly, I6 designates the shell casing, I'I the cap which is adapted to be threaded within the casing I6 and to contain the conventional type of time fuse. This cap preferably has formed as a part thereof a plate I8 which is relatively quite thick, as shown in Figure 1, and, as in the Bergman patent construction, the purpose of this is to prevent any likelihood of forcing the fuse from the shell body when the expelling charge is ignited and to insure the illuminant body and its associated parts being properly ejected from the rear end of the shell, as will appear more clearly from the remainder of the description. The cap I'I and the plate IB may be formed separately if desired.

An expulsion charge chamber I8 is provided between a plate 20, the plate I8 and a preferably split ring 2|, which latter is shown in Figures 1 and 2. In this chamber I9 an expulsion charge 22 is located so that it may be contained in a perforated bag or loose. A ring 23 is located be neath the plate 29 and may or may not be split. Immediately below the ring the illuminant container I0 is located and has communication with the expulsion charge chamber I9 through orifices 24, so that the llame from the expulsion charge will ignite the illuminant.

Split plates 25, which are at least coextensive With the height of the side wall of the illuminant container surround the container, as shown in Figures 1 and 4, and immediately below the illuminant container is a split ring 26, and below this split plates 2'! which extend to the base 3 of the projectile in much the same relationship as in the Berman patent referred to. The parachute or parachutes which have been heretofore described are packed in the space within the split plates 21 and the suspension lines connected` to the base 3 which forms the Weight to cause the canopies to properly descend, by a swivel 28. This base 3 is held in the shell casing by pins 29 such as described in the Bergman patent.

In view of the fact that the reinforcing rubber ribs I3 are of relatively soft material, their packing within the shell casing with the parachutes will not be diicult, and, as I have already stated, they may be incorporated between all of the panels of the sustaining parachute, or only some, depending upon the need for the supplemental support of the illuminant container and the space available within the shell casing.

Thus when the shell is red from the gun the time fuse comes into operation, the expulsion charge 22 will be ignited, and, as I have stated, will, through the openings 24, ignite the illuminant. At the same time the pressure developed by the explosion will, through the plate 2U, the ring 23, the split plates 25, the ring 26 and the split plates 21 transmit the force developed by the explosion to the base 3 of .the projectile and will force the base from the projectile casing and, at the same time, will force the illuminant and its associated parts and the parachute from the casing without transmitting any force to the illuminant or its associated parts or the parachute canopy.

Gf course the split plates 25, the split ring 26 and the split plates 2l will fall away after expulsion from the casing and the sustaining parachutes and the retarding parachutes will be free to inilate. The parachutes will then float earthward and the illuminant will cast an upward light, but no downward light, with the result that any enemy aeroplanes within the illuminated area will be lighted from beneath and the defending planes may attack from the dark area below the floating parachutes.

While I have illustrated and described the particular embodiment of my invention, I do not wish t0 be limited to the details of construction,

except in so far as may be ma-de necessary by the 2. In an illuminating shell, the combination with a shell body having a removable base, an illumnant container mounted in the shell body adjacent .the forward end thereof, an illuminant in said container, a parachute disposed in the shell body between the illuminant container and the base and having its suspension lines attached to the base and its peak to the container, an eX- plosive charge arranged adjacent the forward end of the shell body forwardly of the illuminant for ejecting the illuminant container, the canopy and the base from the shell and for igniting the illuminant, and means for transmitting the force of the explosive charge directly to the base and for protecting the illuminant and the canopy against the force of said explosion.

3. In an illuminating shell, the combination with a shell body having a removable base, of an illuminant container mounted adjacent the forward end of the shell body, an illuminant in said container, a parachute mounted within the shell body and having its suspension lines attached to said base and its peak to said illuminant container, and means for ejecting the illuminant container, the parachute and the base from the shell body rearwardly of the body, the canopy being provided with means for assisting it in maintaining an iniiated form and for supporting the illuminant container on the inflated canopy.

LOUIS J. ZIMMERMAN.

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