Improvements in or connected with Explosive Projectiles, and in Fuses and Fuse Fittings therefor.
Year: 1899

page_text: Date of Application, 28th Mar., 1899-Accepted, 2nd June, 1899
Improvements in or connected with Explosive Projectiles, and in
Fuses and Fuse Fittings therefor.
I, HARRIS PRIULI HURST, of No. 1103, East Capitol Street, Washington, D.C.,
United States of America, Inventor, do hereby declare the nature of this inven-
tion and in what manner the same is to be performed, to be particularly described
and ascertained in and by the following statement:-
This invention relates to safety fuses or detonators for high explosive and
other shells, and the fittings for the fuses, detonators and shells.
The object of the invention is, first, to produce a fuse or detonator and fit the
same to a shell so that the shell cannot by any possible accident be exploded
prematurely; and, secondly, to simplify and cheapen the construction of fuses and
detonators and their fittings.
The invention consists in a novel construction of a safety fuse having a principal
chamber containing the fittings for operating the safety devices therein, a de-
tonating chamber opening into the principal chamber, and a tube or guide, secured
to the principal chamber, carrying a priming or detonating charge. The passway
or fuse-way of the explosive material of the fuse from the tube or guide through
the principal chamber into the detonating chamber is normally closed by a
barrier preferably arranged as a door or doors moving, by the rotary motion of the
shell when fired from the gun, clear of the passway or fuse-way between the
guide and the detonating chamber so as to permit the priming or detonating
charge to come into proximity to the main or bursting charge during the travel
of the shell. Or, when used with guncotton shell, the same construction is
employed to normally separate the dry guncotton and the fulminate of mercury
or other priming or detonating fuse material, until the shell is fired from the
gun and the barrier moved by the rotary motion of the shell from between the
two explosives of the fuse or detonator, so as to permit said explosives to come
into proximity to each other during the travel of the shell.
To insure the shell against accidental or premature explosion the door or doors,
normally, isolating the detonating chamber and the explosive in the guide, are
positively locked against motion until the locking means are freed by the shock
of discharging the shell from the gun, or not until the shell is rotated rapidly, by
will
any means, for instance, in its passage through the rifled bore of the
gun,
the door or doors open the passway or fuse-way of the explosive material of the
fuse to enable the same to explode or detonate the main or bursting charge of
the shell upon retardation or impact of the shell. As a further precaution against
the passage of the gases from the fuse or detonator, when exploded accidentally
or prematurely, the mouth of the passway or fuse-way, as it enters the detonating
chamber, has an annular ridge terminating in a knife edge over which the hard
metal door, having on its face a soft metal plate, is fitted in such a manner as to
seal the passway or fuse-way, when pressure is applied to the door or doors, as
would be the case upon the accidental or premature explosion of the explosive
material of the fuse.

page_text: H
the ronowinу шапцег, rererence being made to
the drawing, in which:
Figure 1 is a longitudinal section of my invention applied to the base of the
shell, showing the position of the fuse and fittings before the shell is fired from
the gun.
Figure 2 is a similar view, showing the position of the fuse and fittings after
the shell has been fired from the gun.
Figure 3 is a plan of the locking ring used in Figures 1 and 2 looking at the rear
end of the ring.
Figure 4 is a modification of Figure 1.
Figure 5 is a cross section of Figure 4 on line z-z, and
Figure 6 is also a cross section of a modification of Figure 1, looking at the
mechanism from the rear.
Referring to the drawings, reference letters are used to designate the various
parts, and like letters indicate like parts.
The shell may be filled with any suitable bursting charge, of gunpowder, gun-
cotton or any other high explosive, and be of any material design and construction.
The shell, A, has the main explosive chamber, B, closed by a screw plug, C,
and has a detonating chamber, D, attachable thereto or integral therewith,
extending forward therefrom into the shell charge. Attached to plug, C, or
to the shell in any suitable manner, or formed integral therewith, is a principal
chamber, chased at the rear by a screw plug, (", hearing thereon as a separable
piece or integral therewith a tube or guide, I, having a closing screw plug, C
securing therein a fuse or detonator, &, seated upon an annealed copper coiled
spring, H, and normally held against motion by a hard metal screw plug, I,
having a soft or brittle metal shear pin, I', secured in any suitable manner to
plug, I, and engaging with the recess, J, in the fuse or detonator casing or
plunger G, as shown. The plunger is attached to the casing of the fuse or
detonator to give increased weight, if desired, or the plunger may be omitted.
On the rear face of plug, C, are hinge lugs, K and K¹, made integral therewith
or secured thereto in any suitable manner, secured to each of which are hinged
doors, L and L', having weighted arms, M and M', attached thereto and extending
rearwardly therefrom, as shown. Projecting rearward from plug, C, is an annular
ridge, O, at the mouth of the passway or fuse-way into the detonating chamber,
terminating in a knife edge. On the bottom of door, L, is attached a soft metal
plate, P, having an annular groove, P, into which the ridge, 0, snugly fits as
a gas check when the door is in the closed position as shown in Figure 1; and
the door may project inward as a tapering plug, dotted lines.
In chamber, E, is housed a locking ring, Q, Figure 3, having two semicircular
locking ribs, R and R', projecting inwardly from the inner walls of the ring,
leaving two openings, S and S', of any desired size, between the ends of the ribs.
The width of rib, I, is less than that of rib, R, but may be of equal weight by
thinning rib, R, and the ribs may taper in the direction of the opening or unlocking
position. The face of the ribs may be beveled so that, when the ring is in the
locking position shown in Figure 1, the ribs press against the arms, M and M²,
thus locking the doors securely in position and in opening or unlocking the taper
and beveled portions shown in dotted lines insures ease in movement of the
bearing parts. The ring, Q, is normally held from motion by the hard metal
screw plug T, having a soft or brittle metal shear pin, T¹, entering a hole in
the ring, as shown. On the opposite side of shear pin, T', is a screw plug, U, 5
screwed through the wall of chamber, E, and projecting into a longitudinal slot, V,
in the outer wall of ring, Q. Slot, V, extends longitudinally forward beyond
the engaging end of plug, U, and turns at right angles and opens into
a transverse slot, V, shown in dotted lines, Figure 3. In chamber, E, there
is a free space, W, between the lower end of ring, Q, and the plug, C, and the 5
ring. Q, is cut away on the inner wall at X, as shown in Figure 2, thus equalizing
the center of gravity of the shell as door, L', is hinged farther from the center of

page_text: the shell than door, L. A smaller cut is shown at X¹. The ring, preferably,
is cast of brass, bronze or other non-corroding metal.
The operation of my fuse or detonator is as follows: Upon firing the shell from
the gun, the ring, Q, shears off the pin, T, and sets back in the space, W, and
the rotary motion revolves the shell to the right around the ring, Q, until stopped
by the plug, U, coming into engagement with the far end of the transverse slot, V¹.
The openings between the ends of the ribs now being opposite the arms, the rotary
motion of the shell swings the arms outwardly through these openings, thus
throwing open the doors as shown in Figure 2, and the fuse or detonator has
sheared off the holding pin and set back upon the annealed copper coiled spring
which acts as a shock buffer and has no return action. The passway or fuse-way,
of the detonating fuse charge, now being open so as to permit the explosive
material of the fuse to come into proximity to the main or bursting charge during
the travel of the shell; and upon retardation or impact the primer or cap, Y,
in the head of the fuse or detonator is exploded by the nipple or pin, Y¹, in the
far end of the detonating chamber, the walls of which are ruptured by the
explosive fuse material and the main or bursting charge in the shell is exploded
or detonated by the force of the explosion of the priming or detonating fuse
charge. The mouth of the passway or fuse-way is enlarged at the entering of
the detonating chamber, so as to afford easy entrance of the explosive material
of the fuse or detonator, the carrier, G¹, moving it in alignment with the
detonating chamber. The tube or guide, F, may be without or within the prin-
cipal chamber, or partly within and without, as shown, and chamber, D, may
be perforated, channeled or grooved, as shown in dotted lines.
The walls of chambers, B, D and E, and tube, F, may be of any suitable.
material, as, for instance, of steel, and of any desired thickness and strength,
and these chambers may be of any desired size and shape. The weighted
arms, M and M', may be of any desired size and weight, and may be rigidly
secured to the door or doors, or have more or less play; and the weighted ends
may be arranged as pivoted balls that will revolve on the end pieces so as to
produce but little friction upon the locking ring, Q, in revolving to open the
passway or fuse-way. The ring, Q, may be held by a pin and plug inserted from
the interior, or a spring may take the place of the shear pin and stop plug, and
the ring may engage with and open the door or doors by rotary motion. The
hard metal screw threaded portion of the shear pin may be separate from the
soft metal portion or point. The doors, L and L, may be of any desired size
and strength and a single door may be used, or one of the doors, L, for instance,
may be of copper or other soft metal; and other locking means besides the
ring, Q, may be used; as it is apparent my invention covers any equivalent
mechanical means for holding the door or doors in the closed position and
releasing the same, and swinging the door or doors backwardly to open and
clear the passway or fuse-way during the travel of the shell. The screw threaded
openings may have washers or gas checks.
Any fuse or detonator may be used, and, if wet guncotton is used as a bursting
charge in the shell, the fulminate of mercury or other priming or detonating
material, N, may be placed in the detonating chamber, dotted lines, Figure 2,
and the dry guncotton, Z, used as a priming or detonating fuse charge, occupy
the tube or guide, or vice versa. The fuse or detonator, as shown, may be
placed in the head of the shell, or at any desired position in the shell cavity
without altering the general design, and the fuse may be made as a separate
attachable piece to be attached to the shell when used. The plunger, G¹, is
constructed and fitted in the fuse tube or guide, F, so as to keep the fuse or
detonator, G, clear of the chamber walls and prevent the heating of the explosive
material of the fuse or detonator: the length of which is sufficient to permit
its entrance into the mouth of the detonating chamber before the carrier is
free of the open end of the tube or guide. A shear pin, I", dotted lines, may be..
if desired, placed in front of the fuse or detonator, especially when a delayed

page_text: fuse action is required. Rubber or other centering and shock buffer studs, H¹,
are placed in the casing of fuse or detonator, G. Additional gas check material
may be placed on the face of door, L, as shown in dotted lines.
Referring now to the modification shown in Figures 4 and 5, the barrier is
composed of doors, L2 and L³, secured in the principal chamber, E, of the 5
attachable fuse holder by pivot pins, K and K³. Projecting from the mouth
of the detonating chamber, 1), and the tube or guide, F, and on the inner face
of the doors are annular ridges, 0, 0³ and Ŏ, terminating in knife edges,
normally resting against the copper plates, P2, P3 and P. Copper plates, 1"
and P, are used as gas checks, and copper plate, P³, is intended to keep the 1
doors from slipping when pressure is applied the ridges, 03, cutting into the
copper plate. The doors have arms, M and M", provided with cog teeth meshing
with corresponding ribs or cog teeth, R and R³, on the inner surface of and
extending longitudinally across the locking ring, Q', which is normally held
from motion by tapering shear pins, T and T. A small spring, h, may be 1
used to push the fuse or detonator, G, into chamber, 1), when the doors have
been thrown open, and a small coiled spring, h, may be attached to the head of
the casing to keep the cap, Y, free of the closed doors. The spring, when the
doors are thrown open, surrounds pin, Y, and on retardation or impact of the
shell the pin explodes the cap, Y. The plunger or plate, G³, is provided with 1
a ball bearing. Ring. Q', has inner weighted sections, M and M, as aids in
unlocking and opening the dors. Arms, M and M, may be weighted for the
same purpose, and, if weighted, other locking means could be used.
The operation of the safety devices illustrated by Figures 4 and 5 is as
follows: Upon firing the shell from the gun, the ring, Q¹, shears off pins, T
and T3, and sets back into the free space, W, and as soon as the set back pressure
is relieved, which is not until the shell has obtained its maximum velocity, the
rotary motion revolves the shell around ring, Q, the ring moving the doors,
by the cog gearing, in the same direction that the shell is revolving, that is,
to the left, if Figure 5 be regarded as a front view, or to the right, if Figure 5
is viewed from the rear, as shown in dotted lines, the ring moving the doors by
mechanical means due to the rotary motion of the shell itself without the aid of
centrifugal force. Upon retardation or impact the fuse or detonator is exploded
in the chamber, 1), by the pin, Y, exploding cap, Y, as heretofore described.
In Figure I show another modification of Figure 1, the locking ring, Q,
having ribs, R and R5, projecting from the inner walls of the ring; the ribs,
and the stop plugs, U₁ and U, secured to the front wall of chamber, E, holding
the pivoted doors, L and L5, in the closed and locked position, as shown in full
lines. The ring, Q, is locked by the curved ends of springs, t and t¹, attached
to the ribs and firmly grasping the plugs U and U. The springs may have
weighted ends, as shown, so as to be thrown out of locking engagement by
centrifugal force due to the rotary motion of the shell when fired, as shown in
dotted lines, or the ring may set back to free any locking means.
The operation of the safety devices illustrated by Figure 6 is as follows:
Upon firing the shell from the gun, the rotary motion, imparted to the shell by
the rifling, revolves the shell to the right around the ring, Q³, the locking
springs, and t, yielding to centrifugal force, or to the weight put upon them
by the ring. As the ribs and the plugs approach each other the plugs pass
under the curved ends of the springs in unlocking. As the shell revolves it
causes the ribs to ride upon the inclined projections, and r¹, on the doors, the
ribs pressing the doors outwardly and the rotary motion of the shell swinging
the doors open, as shown in dotted lines, the doors being so arranged as not
to interfere with the ribs; doors, L', in opening passing over rib, R, and
door, L, passing under rib, R³, and the fuse or detonator is exploded upon
retardation or impact of the shell, in chamber, D, by the pin, Y, exploding cap, Y.
as already fully described. Chamber, D, cap and pin are, therefore, not again
shown.

page_text: In Figure 4 an annular air space is shown around tube or guide, F, and
this feature may be applied to the other designs. The doors, L2 and L³, may
be pivoted to the base, C, and this construction is preferable where an accidental
or premature explosion of the fuse or detonator would rupture and separate the
rear extension of chamber, E, or the tube or guide, F, shown in Figures 1 and 4,
from the rear of the chamber or from the shell; the barrier blocking and sealing
the passway or fuse-way and preventing the igniting or detonating of the main
or bursting charge contained in the projectile.
The cuts, X and X', shown in all the locking rings afford an increased space for
the doors, which, when open, lie or lock in these cuts, and the rings at these
places, upon an accidental or premature explosion of the fuse or detonator, would
expand and lock and wedge the rings in the chambers, E; thus preventing the
doors from unlocking and opening.
These cuts may extend through the walls of the rings, or the rings may be open
rings or have open spaces in the walls, or may be made in any suitable form
as encompassing or encircling locks for the barriers. By reducing the width of
ring, Q, adjacent to the space, W, the ring would unlock the arms, M and M',
by the set back of the ring upon firing the projectile, and this ring may be
so modified.
I claim the invention broadly and do not desire to limit myself to the locks,
barriers and fittings, or whether the door or doors in opening swing backwardly
or laterally in the same or reverse direction as the rotation of the projectile.
It is apparent to one skilled in the art that many modifications may be made
of my invention without departing from the letter, spirit and scope of the same.
It will be seen that the fuse or detonator may be composed of fulminate of
mercury alone, or in combination with gunpowder, guncotton, or any other
suitable explosive, and the material used contained in a single package, as shown
in Figure 1, or divided, as shown in Figure 2, using, if desired, either of the
modifications shown in Figures 4 and 6, to separate the explosives composing the
fuse or detonator.
Having now particularly described and ascertained the nature of the said
invention and in what manner the same is to be performed, I declare that what
I claim is:-
ما:
1. A safety fuse, for explosive projectiles, having a chamber containing a
barrier normally closing the passway or fuse-way therefrom to the main or
bursting charge carried by the projectile, and a lock in said chamber, between
the barrier and the longitudinal walls of the chamber, positively locking the
barrier in the closed position until the travel of the projectile moves the lock,
into unlocking position, and the barrier clear of the passway or fuse-way.
2. A fuse, for explosive projectiles, consisting of a principal chamber carrying
a safety lock, a tube or guide containing priming or detonating explosive
material, a detonating chamber, and a barrier normally closing the passway or
fuse-way between the tube or guide and the detonating chamber; said barrier
positively held in the closed position by the encircling lock until the projectile
is fired from the gun, and the lock thereby put out of locking position and the
barrier moved clear of the passway or fuse-way.
3. A fuse consisting of a principal chamber containing the safety devices
thereof, a detonating chamber leading therefrom, a guide carried by the prin-
cipal chamber, carrying a priming or detonating material, a barrier normally
closing the passway or fuse-way between the detonating chamber and the ex-
plosive material in the guide, and a ring, encircling and holding said barrier in
the closed position and releasing and moving the barrier clear of the passway or
fuse-way by the rotary motion of the shell when propelled by the gun.
4. A fuse consisting of a principal chamber, a detonating chamber, a tube or
guide for the explosive material of the fuse, a barrier normally closing the pass-
way or fuse-way between the detonating chamber and the explosive material in

page_text: the guide, and a ring in the principal chamber engaging and locking the barrier
in the closed position, and releasing said barrier to move and open the fuse-way
or passway during the travel of the shell.
5. A fuse, for explosive projectiles, carrying therein a barrier normally closing
the passway or fuse-way therefrom to the main or bursting charge contained
in the projectile, and a lock encircling and moving said barrier clear of the
passway or fuse-way during the travel of the projectile.
6. A fuse consisting of a detonating chamber, a guide in alignment therewith
carrying therein priming or detonating explosive fuse material, a barrier normally
isolating the detonating chamber and the explosive in the guide, and a locking
ring holding the barrier in the closed position and unlocking the same by the
shock of discharging the shell from the gun; said barrier moving to uncover said
passway or fuse-way by the rotary motion of the shell.
7. A fuse having the passway or fuse-way thereof closed by a door carrying
thereon a weighted arm; the rotary motion of the shell, when fired from the
gun, moving said arm and opening said door clear of the passway or fuse-way
during the travel of the shell.
8. A fuse having the passway or fuse-way thereof normally closed by a trans-
verse barrier, a surrounding locking ring, and means to move said barrier back-
wardly to substantially a longitudinal position, thereby opening the passway or
fuse-way during the travel of the projectile.
9. A fuse composed of two explosives separated from each other by a barrier
moving backwardly clear of the passway or fuse-way, connecting the said
explosives, during the travel of the shell.
10. A fuse composed of two explosives separated from each other by a barrier;
means to hold or lock said barrier in the closed position, and other means to
move said barrier backwardly clear of the passway or fuse-way, connecting said
explosive, during the travel of the shell.
11. A fuse consisting of a tube or guide carrying a priming or detonating fuse
charge, a detonating chamber enclosing a different priming or detonating fuse
charge, a barrier closing the passway or fuse-way between said chambers, and a
ring locking the barrier in the closed position; said ring moving the barrier from
between the tube or guide and the detonating chamber, to permit the two
explosives of the fuse to come into proximity to each other during the travel
of the projectile.
12. A fuse having a spring attached to the head of the casing of the explosive
material thereof.
13. A fuse provided with yielding means to check the rearward movement of
the explosive material thereof, when the shell is fired from the gun, and a
spring attached to the head of the case enclosing said explosive material.
14. A fuse provided with yielding means to check the rearward movement of
the explosive material therein, and a spring to return said explosive material.
when the shell is fired, into proximity to the main or bursting charge contained
in the shell.
15. For use in an explosive projectile, a shear pin composed of a hard metal
body carrying a soft or brittle metal contact or shearing portion therewith.
16. For use in an explosive projectile, a locking ring having interior projection
bearing upon and holding in locking position a barrier normally closing the
passway or fuse-way of the explosive material of the fuse.
17. For use with an explosive projectile, a fuse holder provided with a barrier
normally closing the passway or fuse-way and locked therein by an encircling
lock moving in a chamber to unlock the barrier, whereby the passway or fuse-way
may be opened during the travel of the projectile.
18. For use with an explosive projectile, a fuse holder containing a principal
chamber, a tube or guide opening therein, a passway or fuse-way therefrom
closed by a barrier held in the locked position in said chamber by a locking ring

page_text: in engagement with the barrier; said ring unlocking said barrier to open the
passway or fuse-way during the travel of the projectile.
19. A projectile containing a main or bursting charge, a fuse or detonator
provided with a barrier normally closing the passway or fuse-way; said barrier
composed of hard and soft metal plates, an annular groove in one of said plates,
and a corresponding annular ridge, projecting from the mouth or entrance into
the detonating chamber, in engagement with said groove, to check the passage
of gas upon the accidental or premature explosion of the explosive fuse material;
Faid barrier moving by the rotary motion of the projectile during the travel of
the projectile to open the passway or fuse-way.
20. A projectile carrying a main or bursting charge, a fuse or detonator, a
barrier normally isolating the charge from the fuse or detonator, and means to
move said barrier backwardly to substantially a longitudinal position during the
travel of the projectile.
21. A projectile enclosing a main or bursting charge, a fuse or detonator
isolated by a barrier having a weighted arm thereon, said arm moving said
barrier, clear of the passway or fuse-way, during the travel of the projectile.
22. A projectile containing a main or bursting charge, a fuse or detonator, a
barrier normally closing the passway or fuse-way and locked therein by a ring
in engagement therewith; said ring and barrier moving and opening the passway
or fuse-way when the projectile has been propelled by the gun.
23. A projectile containing a main or bursting charge, a fuse or detonator
isolated therefrom by a barrier locked in the closed position by a ring constructed
to set back and release itself by the firing shock, and revoluble to move said
barrier clear of the passway or fuse-way during the travel of the projectile.
24. A projectile containing a main or bursting charge, a fuse or detonator, an
isolating barrier held by a lock in the closed position by a hard metal stud having
a soft or brittle metal shear pin.
25. A projectile charged with a main or bursting charge, and a fuse or detonator
normally held by a hard metal stud having a soft or brittle metal shear pin
constructed to shear by the set back of the fuse or detonator when the projectile
is fired from the gun.
26. A projectile containing a main or bursting charge, a fuse or detonator, an
interposed barrier locked by a surrounding ring having recesses in the inner
wall thereof, said barrier and ring moving by the rotary motion of the projectile
to open the passway or fuse-way thereof during the travel of the projectile.
27. A projectile carrying a main or bursting charge, a fuse or detonator there-
for having centering and yielding studs thereon.
28. A projectile carrying a main or bursting charge, a safety fuse or detonator
having a chamber containing therein means for closing, locking and opening the
fuse-way thereof; said closing means constructed to seal said fuse-way, and said
locking means wedge in said chamber by gas pressure, upon the accidental or
premature explosion, of the priming or detonating material of the fuse or
detonator.
29. A projectile having a main or bursting charge, and a fuse or detonator
carrying a holding and releasing lock surrounding and locking in the closed
position a barrier normally closing the passway or fuse-way of the explosive
material of the fuse or detonator; said barrier moving clear of the passway or
fuse-way during the travel of the projectile.
30. A high explosive projectile having a main chamber enclosing a bursting
charge, an isolated chamber carrying the priming or detonating charge, and a
barrier normally separating said chambers and moving by the rotary motion of
the projectile without the aid of centrifugal force, during the flight of the
projectile, to permit the priming or detonating charge to pass into proximity to
the main or bursting charge.
31. A high explosive projectile containing a chamber for the main or bursting
charge, an isolated chamber having a priming or detonating charge, a barrier

page_text: between said chambers constructed to move to open communication between
the chambers when actuated by the rotary motion of the projectile during flight,
and means for locking said barrier in the closed position, said locking means
releasing and moving said barrier during the flight of the projectile.
Dated this 27th day of March 1899.
WM. P. THOMPSON & Co.,
Of 6, Lord Street, Liverpool, Agents for the Applicant.