Improvements in and relating to Projectiles.
Year: 1889

page_text: Date of Application, 26th Nov., 1889-Accepted, 4th Jan., 1890
COMPLETE SPECIFICATION.
Improvements in and relating to Projectiles.
I, PETER JENSEN, of the firm of Jensen and Son, Patent Agents, of number 77,
Chancery Lane, London, England, do hereby declare the nature of this invention and
in what manner the same is to be performed, (a communication to me from abroad
by The Pneumatic Dynamite Gun Company of 71 Broadway in the City and State
of New York one of the United States of America), to be particularly described and
ascertained in and by the following statement :-
This improvement relates to hollow elongated projectiles, and particularly such as
are used to contain dynamite or other high explosives, and generally to be propelled
from a pneumatic or similar cannon.
Tubes have been heretofore made by winding thin metallic ribbons spirally in
layers, which layers were soldered together. Such tubes are well adapted to form
the cylindrical body portion of these projectiles, but other drawn or rolled tubes may
be used.
In making projectiles of these spirally wound tubes, it is desirable that the front
of the projectile be the lightest, and as this part of the projectile is less exposed to
the pressure of the gun, it inay be made of thinner tubing. The projectile may be
made in sections, joined by rings or transverse partitions against which the ends of
the tubes abut.
Referring to the accompanying Drawings:
Figure 1, is a longitudinal central section of the casing of a projectile, the point
being broken away;,
Figure 2, is an enlarged section of a broken portion.
A, indicates the cylindrical body of the shell; A¹, being the forward tubular por-
tion; A2, the central tubular portion; and, A³, the rear tubular portion.
The front portion, A¹, is thinnest, and the tubes, A³, and, A³, toward the rear
increase in thickness by additional layers. The outer and inner layers may be of
brass, and the intermediate layers of steel. The layers are in the form of flat
ribbons, a, wound spirally and joined by solder, a¹. (Figure 2.)
As the projectile is to have a rapid rotation on its axis, the separate tubular
sections, A1, A2, A3, are balanced by the addition of solder, as at, w, fig. 1 or in any
other convenient manner, so that each pair balances. The entire projectile when
assembled is also made to balance, as by the addition of solder to the point, B,
diaphragm, M, or other part.
The front edge of the front section, A¹, abuts against a shoulder, b, of the cast-
metal point, B, the lip, B', extending inside the said tube, A¹. The rear end of
tubular section, A', rests against the flange, M³, of the rigid diaphragm or parti-
tion, M.
The tubular section, A2, abuts against the flange, M2, of partition, M, and also.
against the flange, P2, of partition, P, and the tubular portions secured by screws, m,
entering the lips of the partition or diaphragm. The hold of the screws on the
tubes and diaphragms may be strengthened by inserted bushings, as hereinafter
explained.
The diaphragm, M, serves to divide the explosive charge. The diaphragm, P,
is the real base of the projectile, and contains the rear fuse or fuses.
The sabot or gas-check is dropped from the projectile, after it leaves the gun.
Several forms of gas-checks may be used.
The sabot, G, is preferably composed of layers of wood, with the grain crossing,
and has an expansible gas-check, G', which operates in usual manner to fill the
bore of the gun. The ring, C, entering the rear of the tube, A³, is not secured
thereto, but serves to center the projectile in the gun. The entire sabot drops off

page_text: after the projectile leaves the gun, leaving the tube, A³, as a guiding tail. Centering
blocks or shoes, as will be hereinafter described, are applied to the forward part o
the projectile to center it in the gun.
Figure 3. is an elevation, and
Figure 4, a longitudinal section of the projectile showing centering flanges, and
the wings for giving a rifled motion to the projectile.
Figure 5, is a section on line, -a, looking toward the base of the shell ;
Figures 6 to 10, are details of construction.
In the construction shown in Figure 4, the cylindrical sections, A1, A2, may be of
coiled ribbon hereinbefore described, or they may be of other known material. The
dividing partition, M, may be secured as hereinbefore described in Figure 1, or may
be integral with the cylindrical parts, the object of this diaphragm being to
sustain the "set back" of the front portion of the explosive charge when the gun
is fired.
The rear partition, diaphragm, or base, P4, may be integral with the tubular
extension, A, or be firmly secured thereto. The diameter of the projectile and wings
is a trifle less than the caliber of the gun.
Packing pieces, d, of leather, indurated fiber, or similar material, are firmly
attached to the wings, so as to just fit the bore of the gun, and present a non-metallic
bearing surface thereto. By these wings the rear end of the projectile is exactly
centered in the gun.
The forward end of the projectile is centered by blocks or shoes, H, of brass or
other elastic metal. Three or more of these centering blocks may be used. The
blocks are faced with pieces, d¹, of leather or fiber, which pieces exactly fit the
bore of the gun. These centering blocks are of several forms, as will be explained.
A cross-section of one of the blocks, H, and its retaining flange is shown in
Figure 6, and a section on line, -z, in said Figure 6, is shown in Figure 9. The
blocks, H, are hollow and have a slight dove-tail at the base, h. where they rest
between ribs, I, on the body of the projectile, said ribs being slightly undercut.
The ribs, I, form a box on the surface of the projectile, open at the front and partly
closed at the rear. The blocks, H, fit these boxes closely, but the dove-tails do not
engage until the base of the block is expanded by the wedge, K³, which passes
through slot, H', in the base of the block, H. The wedge, K, is at the forward end
of a flat bar, K, and bar, K, extends back from each block, H, and is held by a
pintle, K, to a lug, K', on the gas check or ring, J. The extreme front of the
bar, K, forms a head to hold the block, H, from moving forward. The bars, K,
are held to the body of the projectile by screws, K³, of brass, or other soft meta!.
The gas-check, J, is a hollow ring which nearly fits the bore of the gun. Around
the periphery of this ring there is a groove, which contains a packing ring, J, of
leather, or other suitable material, which fits the bore of the gun. Small passages
lead from the rear of the gas check under this packing ring, and conduct the air or
gas used in propelling the projectile under the packing ring, thus expanding the ring
to tightly fit the bore when the gun is discharged.
The gas check has a flange, J, which extends forward into the tube, A4, but the
body of the gas check before firing, is a little in the rear of the tube, A', of the
projectile, and held in this position by the pins or pintles, K2, which join the
bars, K, to the lugs K¹, on the ring, J.
When the projectile is fired the ring, J, is pressed forward by the air or gas in
the gun, and screws, K³, are sheared off, permitting the bars, K, to move forward
until the ring, J, rests against the base of the projectile. This loosens wedges, K³,
and permits the blocks, H, to spring together, so that the dove-tails do not interlock,
but as the outward faces of these blocks rest against the walls of the gun, the blocks
will lie between the ribs, J, until the projectile leaves the gun, when the blocks will be
thrown off from the projective by their resistance to the atmospheric pressure. The
bars, K, will also be free, and with ring, J, will be thrown back by the atmospheric
resistance, leaving the projectile free to fly unimpeded by said projections. The
wings, D³, engaging the air, give a rotary motion to the projectile."

page_text: The ring, J, has strengthening ribs, Figure 7, and has also radial lugs, J³,
projecting inward and serving to hold rods, L. These rods, L, extend forward nearly
to the fuses, G, and may serve as circuit breakers therefor when electric fuses are
used. The rods, L, may be adjusted in the slots in lugs, J³.
Figure 11, is a central longitudinal section of a full caliber projectile having
collapsible head, partly broken away for convenience of illustration;
Figure 12, is an enlarged view of the head of the same, slightly modified.
Figure 13, is a central longitudinal section of a sub-caliber projectile broken at
several places to reduce length.
Figures 14, 15 and 16, are detail views hereinafter explained.
The full caliber projectile, Figure 11, has a cylindrical body portion, A*, which is
divided by one or more transverse partitions, Mx, the partitions serving to divide
the mass of the explosive charge, and to sustain the "set back," when the charge
is fired.
The internal cup, 1, is the confining case for the front of the explosive. The open
thimble, 2, is insulated from the body of the projectile, but connected with one of the
poles of the electric fuse.
The metallic point, B*, is of metal which will collapse on striking a solid target, as
an armor plate, and when it is collapsed against thimble, 2, circuit is closed between
the poles of the enclosed battery, and the primer is ignited.
The metallic body of the shell is held out of contact with the bore of the gun by
fillers, 4, of leather, indurated fiber or the like. These fillers seat in recesses, 5, in
the outer casing, and are held to place by counter-sunk screws, 6.
Where the inserted fillers come opposite a joint in the cylindrical portion of the
shell, the outer tubes may be cut away and the filler inserted in the opening, so as to
rest on the inner tubes. (See Figure 16.),
To prevent the shearing of the screws which join the tubular sections, as might
happen from the shock of firing, a recess, 7, is drilled or cut through the outer
tubular section, and into the wall of the inner tube, point, partition, or whatever is
inside the outer tube. This recess is much larger than the body of a common screw,
and is preferably cylindrical. A bushing, 8, which exactly fills the recess, is inserted,
and a screw 9, counter-sunk therein, extending well into the inner portion or
partition. (Figures 17 and 18.) The tendency to shear off the screws is thus
overcome, as the bushing must shear off before the tube sections can have longi-
tudinal play.
The
The shoulder, 10, near the base of the projectile, gives a seat for the gas check, 11,
which is composed of rings of leather or fiber passing entirely round the body of
the projectile, and turned back against the rounded shoulder. A metallic ring, 12,
surrounds the gas check, and is secured to the body of the projectile by screws.
effect of this curving back of the gas check is that the projectile may readily enter
the bore of the gun from the breech, but when the gun is discharged the air or gas
rushing forward encounters the turned up edges of the leather or fiber bands, and
expands them against the walls of the gun, making a close fit.
It sometimes happens that the projectile is to be entered toward the breech instead
of toward the muzzle of the gun. In such case a different gas check may be used.
(See Figure 16.) An annular recess, 16, passing entirely round the projectile,
receives rings, 17, of leather, fiber, or soft metal, the rings being of such size as to
exactly fit the bore of the gun.
A number of air passages, 18, lead from the rear of the ring or rings, 17, to the
recess, 16.
When the projectile is fired the air rushes into these passages, 18, and
passing round under the rings, 17, expands said rings so that they crowd the
bore and prevent the escape of gas forward.
The tail or guiding spindle, 20, of the full caliber projectile, bears two spiders, 21,
and, 22, one of said spiders being at the extreme rear end of the spindle, the other
about mid-length thereof.
These spiders have radial arms inclined like a screw propeller. Wings, 23, 23,
extend from flanges at the base of the projectile body to the spider at the end of the

page_text: spindle, and are firmly secured to the body of the projectile and to the arms on the
spiders. Shorter wings 24, extend between the spiders and are secured to the arm
of each. The projectile thus has two sets of spiral guiding wings which tend to rotate
the projectile on its axis during its flight through the air.
The sub-caliber of the projectile, Figure 13. is shown much shortened, the body of
the projectile being broken away through the charge chambers, T, T, T. The point
of the projectile may he weighted at, 25, with lead or other heavy substance which
will bring the center of gravity well forward. The blocks or shoes, H*, will be made
to drop from the projectile, and the spiral wings, DX, will fill the bore of the gun
and center the projectile therein. A sabot or wad must be used in rear of this
projectile. (Sce Figure 19.)
The rearwardly projecting cup, 26, integral with the rear section of the projectile,
serves to support this sabot or wad, which drops after the projectile leaves the gun.
A passage, 27, permits the insertion of the fuse into fuse-chamber, 28, and
passage, 29, provides for the insertion of a front fuse.
a
It will be understood that the charges of dynamite or the like: in the separate
charge chambers of the projectile are inserted before the sections are finally secured
togetber, and that electric wires, when necessary to make circuits with the primers,
are placed in the projectile while the same is being loaded. The final insertion of
the fuses and connection of the same to the wire will be made only when the projectile
is about to be loaded into the gun.
Figure 19, is a section of the rear end of a projectile showing a mechanism for
throwing off the centering ring or sabot:
Figures 20 and 21, are details of the centering blocks or shoes at the front of a
sub-caliber projectile.
Figure 22, is a broken central longitudinal section of a projectile showing electrical
fuses in place.
The cylindrical body, A, Figure 19, of the projectile has the shoes, H, and the
wings, D³, hereinbefore described, and may have the fuses, partitions, &c. hereinbefore
referred to.
The centering ring or gas check, 30, is a cup with its mouth toward the rear, and
has a central depression or reverse cup, 31. The central portion of the gas check
has the hole or holes, 32, and these are covered by a flexible valve, 33. A disk
of metal, 34, is secured in front of the flexible valve to limit the movement thereof.
The base, 35, of the projectile has annular flange, 36, extending rearward, which
flange enters and fits the depression. in the gas check. The joint between the gas
check and projection, 36, may be closed by packing.
When the gun is fired compressed air or gas will enter hole or holes, 32, and fill the
space or chamber, 37, between the gas check and base of the projectile, but as the
pressure from the rear of the gas check is greater than that from the front, the gas
check will be held firmly against the base of the projectile. When the projectile
leaves the gun, however, the compressed gas in the space, 37, will expand, and force
the gas check or ring from the projectile, (being assisted by the back pressure of the
air on ring, 30.) The projectile will then present a smaller surface and of course be
less resisted by the air in its flight.
H³, Figure 20, indicates a centering block or pin which is held to the body of
the projectile by a catch which is unlocked on entering the projectile into the
gun. The block, H3, having a contact surface of leather or fiber, as before described,
has pins, 40, and, 41, which enter recesses in the body of the shell. A pivoted lever,
42, has one arm, 43, projecting beyond the surface of the block, and has a spring
catch, 44, which enters a recess in the shell, to hold the shoe or block to the shell
when arm, 43, projects. The entry of the projectile into the gun depresses lever, 43,
and withdraws the catch, 44, unlocking the shoe, but as long as the projectile is in the
gun the pins, 40, and, 41, will hold the shoe in place. As soon as the projectile
leaves the gun, the air pressure against the inclined front, 45, of the shoe will throw
said shoe from the projectile, the pins, 40, and, 41, being shaped for easy attachment.
The shoe, H, Figure 21, is made detachable by the set back" in firing. The

page_text: shoe has a sliding bolt, 46, which bolt carries two hooks, 47, and, 48. These hooks
engage with hooks on the body or point of the projectile when the bolt is pressed
forward, and when the hooks are engaged the bolt is held from moving by a friction
spring 49. The rear end of the bolt may pass through an airtight bushing, 50, in the
shoe, and the front will be in a suitable bearing, 51, in the shoe, and open at the front
thereof.
When the projectile is fired the inertia of the bolt 46, causes it to remain at rest
when the shell starts, thus unlocking the bolt, the movement of the bolt relatively to
the shoe being assisted by the air-pressure on the front of the bolt.
These shoes, H³, and, H4, may be used alternately around the projectile, or all the
shoes may have the same means for fastening, such means being any of those here-
tofore described.
In Figure 22, the point of the shell, Bx, the shell body, A, the partition, M, and
other parts of the shell are constructed substantially as has been heretofore indicated.
The chambers, 55, and, 56, which contain the explosive charge are shown as broken, to
reduce the length of the projectile, which is usually from five to twelve calibers.
The point, 60, has a screw-threaded hole to receive the electric fuse, 61. This is
what is known as a dry battery fuse, the inner cell of this battery is connected by
metallic connections to the electric igniter, 66. The outer cell, 65, of the battery,
when sensitized, completes circuit through the metallic fuse casing, but when dry acts
as a circuit breaker.
A disk or cap, 63, is held by spring, 64, against the inturned flange, 67, of the outer
fuse cap.
This prevents moisture entering to sensitize the outer battery cell, but
if the projectile enters the water at a high velocity the cover, 63, will be forced
in by the water pressure, and water will enter the sensitized, battery and explode
the shell.
All the metallic circuits of the electric fuses are normally broken at two places until
the projectile is fired from the gun. One of the broken circuits closes automatically
as the projectile leaves the gun. The closing of the other, by the projectile dropping
into the water, or by striking a target, explodes the projectile. The circuit closer
of the front dry battery is an insulated plunger, 80, which is held out of metallic
contact with the metal of the front battery by an insulated pin, 81, passing through
the fuse casing and plunger. The shock of striking of the projectile causes the
shifting of the plunger and closes circuit.
The electric fuse, G*, in the base of the shell is connected by means of tube, 70, (or
wires passing through this tube or in other convenient location) to wire, 71, which
completes circuit with the thimble, 2. The electric battery, 101, in the fuse, G*, is wet
and sensitive when the shell is fired, but for safety the electric current from said
battery is held broken by detents, 72, until the projectile is loaded into the gun, and
these detents are released by air-pressure and thrown off when the projectile is fired.
The air pressure serves to hold the circuit broken at the rear of the fuse until the
projectile leaves the gun, when the rear circuit is closed, making metallic connection
in one direction from the primer, 75, to the metallic body of the shell and in the other
direction to the insulated thimble. When the projectile strikes a solid body, as an
armored ship, the point, Bx, crushes in and makes metallic contact with the thimble, 2,
closing circuit and igniting the charge at the base of the projectile, (at primer, 75) so
that the explosion is from the rear instead of the front of the bursting charge.
The electric fuse, Gy, is a dry battery fuse, having a metallic connection from one
pole of the battery, 101, through primer, 75, to the metallic casing of the fuse, and
through the other pole and spring, 73, to metallic plate, 90.
The plate, 90, is held away from the metal cap of the fuse casing by insulated
pin, 91, bearing on cover, 92, the cover being held on the fuse case against the
pressure of the spring, 73, by hooks, 93. When the air-pressure comes on cap, 92,
said cap will be pressed forward, and the spring hooks, 93, will release themselves.
As soon as the projectile gets beyond the influence of the air-pressure, the spring,
73, will throw off the cap, 92, and press plate, 90, against the fuse case.
The

page_text: circuit will then be closed when water enters the fuse, Gy, and sensitizes the battery.
The circuit breaker of fuse, Gx, is actuated in a manner similar to that of circuit
breaker of fuse, G. In some instances an impact fuse is used instead of or in
addition to the electric fuse. In such case the form shown in Figures 23 to 25, may
be adopted.
Figure 23, is a broken section through the longitudinal central part of a shell.
Figure 24, is a central section of the front part of a projectile in place in a gun.
Figure 25, is a cross-section on line, -a, Figure 23.
The shell body A a, Bb, may be of the general character before described. The
point has a recess, 102, and the base a recess, 103. A cup, 104, behind the recess, 102,
may be integral with the point of the projectile. The recess, 102, may be bored out
from the front to make a seat for the fuse casing, 106, which is held in place by the
threaded cap or anvil, 107, engaging a screw-thread in the recess. The base or
plunger, 109, of the fuse slides easily inside the casing, 106. This plunger is in
form of a ring, and surrounds the rod, 120, which passes through the front fuse and
terminates at the front in a head, 121, of such diameter is to fit nicely in the
recess, 102, forming a piston therein.
The plunger, 109, carries a number of nipples, 111, which have fulminate caps
at their front ends, and detonating charges, 110, connected to the nipples. The
detonators, 110, are sufficiently powerful to rupture the fuse case and ignite the charge.
A wire or wires, 112, of light and frangible or flexible material, holds the
plunger, 109, back from the cap or anvil, 107, until the projectile strikes " "point
on with considerable force, when the plunger, 109, is thrown forward, buckling
the wires, 112, and bringing the caps on the plunger forcibly against the anvil, thus
exploding the caps.
"
Each cap of the front fuse communicates fire to a slow burning charge, 108, to give
a little delay, and permit the projectile to enter the water a little distance before
exploding the detonating charge, 110.
"
The detent, 112, which retains the plunger, 109, is so slight that the plunger will
move forward when the projectile strikes the water "point on.' The plunger, 109,
may be of considerable weight.
If the projectile strikes a solid target, as an armor plate, the rod, 120, and piston,
121, will tend to move forward, in the recess, 102. But in the water the piston, 121,
will be held back by the pressure of water in chamber, 102.
The rod, 120, extends nearly to the rear of the projectile, and screws into an annular
plunger, 130, of the rear fuse.
A headed cap, 125, screws into the rear end of this ring, 130, and a soft metal
washer, 122, interposed between the cap, 125, and the base of the fuse, holds the
rod, cap, and plunger against forward movement until the washer ruptures or
draws in when the rod and plunger will move forward together.
The ring, 130, carries nipples provided with detonating caps, 129, and these parts
are inclosed in a light tube, 128. The front wall of fuse case, 124, serves as an anvil,
and the detonators, 129, will be exploded against this anvil when the projectile in its
flight strikes a solid target, by the yielding of washer, 122, and the forward movement
of piston rod, and plunger.
The ring, 130, can be taken out to apply the detonators by unscrewing the
cover, 126, and cap, 125, when the washer, 122, can be taken off, and the ring, 130,
unscrewed from rod, 120.
Webs, 127, serve to stiffen the fuse case, and support the tubular casing, 128.
The piston rod, 120, is preferably made hollow, for lightness and strength, and is
preferably surrounded by a light tube, 119, which enters the bottom of cup, 104, and
the front end of the rear fuse casing, 124.
The rear fuse will act instantly to fire the charges at the rear on striking a solid
target, but will be held against action by the piston rod if the projectile falls into the
water. The front slow acting fuse gives a little delay, so that on striking a solid
target the charge will be first fired at the rear.

page_text: When used with a sub-caliber projectile we may add to the wire, 112, which serves
as the detent for the plunger in the front fuse shell, a spring bolt, 113, inserted from
the side of the shell. This bolt has two prongs, 114, and, 115, one of which enters a
hole in the side of the plunger, 109, and the other interlocks with the piston rod, 120,
thus holding both against forward movement. (See Figure 24.)
The outer end of the spring bolt, 113, passes through a hole in the side of the shell,
and by its spring, 117, is held normally out of engagement with the plunger and rod,
the outer end coming flush with the surface of the projectile, or projecting therefrom.
One of the shoes, 133, which serves to center the projectile in the gun bears on and
forces the bolt, 113, inward when the shoe is in place, causing the prongs, 114,
and, 115, to engage with the plunger and rod, as before described.
When the projectile leaves the gun the shoe, 133, flies off, and the spring, 117, of
the bolt, 113, forces the bolt outward, thus releasing the detents, 115, and, 114. The
shoes, 133, are held to the projectile by mechanism heretofore described, and when so
held will retain the bolt, 113, in depressed position.
In full caliber guns, the walls of the gun may serve to hold the bolt, 113, depressed.
The rod, 120, may contain electric wires, if an electric'fuse is used in addition to
the impact fuse.
Figure 28, indicates a mechanism for detaching the gas check or sabot, by
unscrewing the same. The sabot, Je, has a screw-threaded stem or spindle, J7,
which engages a screw-thread in the shell body, A A. The wings, D, D, on the
shell body have a spiral pitch in one direction, while those, d, d, on the sabot incline in
the opposite direction, so as to rotate the sabot and unscrew it from the projectile
while in flight.
Figure 26, is an end view of the sabot with wings, d, d.
Figure 27, is a cross-section of shell showing the layers and inserted bushings of
Figure 17.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed I declare that what I
claim is
1. The construction of the projectile in sections made of tubes of the character
described, and the joining of said sections together and to the partitions in substantially
the manner described to avoid shearing.
2. The centering shoes or blocks on a sub-caliber projectile, and the retaining
rods connecting said shoes to the gas check at the base of the projectile.
3. The movable gas check detachably held to the projectile by rods which by their
movement serve to unlock the centering blocks or shoes in substantially the manner
set forth.
4. The hollow ring gas check and the mechanism for securing the same to the
projectile, and for causing the same to easily enter the bore of the gun and pack
the same when the gun is fired.
5. The jointed sections, and the fillers and bushings by which the projectile is
centered in the gun, and the sections held together and to the partitions so as to avoid
shearing.
6. The spider and spindle, and the double system of spiral wings connected to the
spindle, substantially as described.
7. The throwing the gas check from the base of the projectile by the pressure of
air or gas confined between the projectile and the gas check.
S. The mechanism for holding the shoes to the projectile, and releasing it there-
from by the detent bearing on the walls of the gun.
9. The mechanism for holding the centering shoes to the body of the projectile,
and releasing the same by the "set back" of a part of the detent which can move
back relatively to the projectile.
10. The tubular connection between the rear fuses and the front portion of the shell,
and the electric connections through or by means of this tube, to complete the electric
circuits.

page_text: 11. The mechanism for exploding the shell from the rear by contact with a solid
target, and for holding the plunger when the projectile enters the water, so as to
explode from the front.
12. The construction of the projectiles as shewn on the drawings.
Dated this 26th day of November
1880
avambor
JENSEN & SON,
77, Chancery Lane, London, W.C., Patent Agents.