Improvements in Fuses for Projectiles.
Year: 1899

page_text: Date of Application, 4th July, 1899-Accepted, 2nd Sept., 1899
COMPLETE SPECIFICATION.
Improvements in Fuses for Projectiles.
I, HENRY PARKER MERRIAM, Mechanical Engineer, a citizen of the United
States, residing at 186, West 11th Street, New York, in the County and State
of New York, do hereby declare the nature of this invention and in what manner
the same is to be performed to be particularly described and ascertained in and
by the following statement:-
The present invention relates generally to fuses adapted; for instance, to
detonate high explosives contained by the shell carrying the fuse.
The improvements more particularly relate to that class of fuses wherein is
employed a spherical hammer normally held against movement by a removable
stop and when released arranged.upon impact or retardation of the shell to explode
a percussion cap or primer to fire a charge.
As a more full understanding of the invention will be had by a detailed
description of the improvement, such description will now be given with refer-
ence to the accompanying drawings, in which:-
Figure 1 is a central section of the head of a shell with its contained fuse.
Figure 2 is a like view of a modified form thereof.
Figure 3 is a detail sectional view of the movable firing pin or igniter.
Referring now particularly to Figure 1, the head of the shell A is chambered
to receive a fuse case 10 preferably of cylindrical form capable of longitudinal
movement in the head and adapted to rest at its front against a shoulder 11' in
the head of the shell and at its rear to enter a like shaped recess 12 in a cup-
shaped diaphragm 13 with a spring 15" interposed between the diaphragm and
the ond of the fuse-case to yieldingly seat the latter in the shell. The rear end
of the diaphragm and the hollow end of its sleeved portion is coincident with the
front end of a gun-cotton case 16 screwed into another diaphragm 17 of the
shell so that the fire of the charge contained by the hollow stem and other
channels 9 provided in the fuse-case will be communicated to the fulminate of
mercury and gun-cotton charge in the case 16.
The fuse case is hollow and contains a spherical hammer 20 normally seated
in a concaved recess in the rear wall of the fuse-case; and opposed to said
hammer is arranged one or more firing pins in the form of balls 8 supported by
the fuse-case in position to be struck, or either of them, by the forward impulse
of the hammer. The firing pins are seated above percussion caps or primers 2
seated upon anvils which, when exploded, fire the flash or time charge in the
channel or channels 9.
Instead of depending wholly upon the momentum of the hammer 20 in striking
the ball 8 to explode the primer, there may be an additional arrangement of
firing pins or balls 8 held in a slidable case 8b having an outwardly projecting
pin 7, as best seen in Figure 3; extending through the fuse-case to within a short
distance of the head of the shell; the primer 2 being seated on an anvil in the
slidable case in immediate proximity to the ball 8. In this arrangement, should
the shell strike the target on its side, the inwardly crushing movement of the

page_text: side of the shell in striking the end of the pin 7 together with the momentum of
the hammer 20 in striking the ball 8 will cause a movement of the pin and its
slidable case and the ball with respect to each other so as to forcibly pinch the
primer between the ball and anvil and cause its explosion, and thus fire the
charge in the channel or channels 9. While only one ball 8 and one ball 8ª are
shown it is proposed in practice to employ a plurality of such balls, it being
obvious that the fuse may be used if desired with either form without affecting
the scope of this invention; the two forms are, however, preferably employed.
The hammer 20 is normally held against movement by a screw threaded stein
or rod 18 tapped into the head of the fuse-case and having at its front end a
spirally bladed wheel or propeller 19 capable of being rotated with the stem by
the air during the flight of the shell, to remove the rear end of the stem a
distance from the hammer. Instead of depending entirely upon the withdrawal
of the end of the stem from pliysical contact with the hammer to release the
latter, which in practice occurs immediately after the shell leaves the gun on its
flight, to the dunger of premature explosion by the forward movement of the
hammer, the present improvements provide a secondary nut or removable stop 21
engaged by the screw threaded stem or rod 18 with its end, instead of the stem,
normally in direct contact with the hammer to form a stop therefor, holding it
against movement. This secondary nut 21 is arranged, when freed from the
stem 18, to freely slide forward in a central opening in the head of the fuse-case
upon the impact or retardation of the shell and thereby allows the forward move-
ment of the hammer toward the firing pins 8, 8ª. So long as any portion of the
screw threaded stem 18 is engaged with this secondary nut or stop, the hammer
is prevented from having any movement, but as soon as said stem is freed from
said stop or secondary nut and has moved a short distance therefrom, the nut is
free to move forward whenever the hammer has such tendency. The forward or
detonating movement of the hammer is thus delayed a sufficient extent to ensure
its movement only at the proper time, and so long as the said stem is in engage-
ment with the nut or stop no movement of the hammer can possibly take place.
The secondary or movable stop-forming nut is held from rotation by a pin 3
entering loosely a hole in the front wall of the fuse-case. The distance to which
the shell may be propelled before the stem is clear of the stop or nut 21 will,
of course, depend upon the inclination of the vanes of the propellor and upon
the length of stem screwed into the nut; its length or the distance to which it is
screwed into the nut being obviously capable of being regulated according to
the time at which it is desired the hammer shall be actually free to operate.
In the modified form of the invention shown in Figure 2, a somewhat simpler
form is shown adapted for use with smaller shells and where it is advantageous
that the fuse shall take up the minimum of space.
In this example of the invention, the head of the fuse-case is provided with
a flange between which and the diaphragm 31, and encircling the case, is
interposed a spring 32 to yieldingly seat said fuse-case in the head of the shell.
The bladed shell or propellor 19 is provided as before described, with a screw-
threaded stem 18 tapped into the head of the fuse-case and engaging with the
movable stop or nut 21 which normally is in direct stopping contact with the
spherical hammer 20.
The fuse-case, also in this instance, is made in two parts, the rear portion 33
screwed into the front or major portion, and having a central hollow stem com-
municating with one or more flash charge channels 9 and with the gun cotton
case 16 for purposes alike those previously described.
It will be noted that in the form shown in Figure 1, (it might also be the
case with the structure shown in Figure 2), that the detonation or firing of the
fuse is subject to two conditions. Thus, the channel 9 directly affected by
the operation of the firing pin 8, may be filled with a time train, in which case
a certain predetermined delay will occur after the firing pin has been struck by
the hammer 20 before. the gun cotton in the case 16 will be detonated; while

page_text: the other channel 9 controlled by the movable firing pin 8 and 7 may bo
charged with a quick train, ensuring a positive and instantaneous action upon.
the shell striking a substantially solid target sufficient to cause an indenting of
the shell-head with the forward movement of the hammer.
The fuse-case 10 with its hammer 20, rear socket 14, stop 21 for the hammer,
and the releasing stem 18 and wheel 19 are normally held in the retracted position
shown in Figure 2 by the latch 34 in the fuse-head engaging with the notch 35
in the fuse-case; the spring 15" or 32 exerting a force tending to push the fuse-
case and parts belonging thereto into a more forward position. In this position
the spiral bladed wheel 19 is prevented from being turned by the key 36 fastened
in the fuse-head, engaging with a notch 38 in the wheel 19.
When the shell is given a sudden forward acceleration as in its discharge
from the gun, the spring 15 or 32 is compressed by the fuse-case retreating a
short distance into the head of the shell. This slight rearward movement
operates to push the latch 34 longitudinally in its cavity to a point beyond the
edge of the notch 35. When the acceleration of the shell ceases, i.e., when the
shell leaves the muzzle of the gun, the spring 15" or 32 forces the fuse-case into
its most forward position with the spiral bladed wheel 19 fully projecting from
the cavity in the point of the shell, and removed from the restraining action
of the key 36. The swift movement through the air causes the wheel 19 and
spindle 18 to revolve whereby the detonator is released after the manner already
described.
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. In a fuse, the combination of a hammer, an opposed firing pin or igniter,
a stop for the hammer, and an independently movable device, movable during
the flight of the shell, to disengage the stop to release it, as described.
2. In a fuse, the combination of a hammer, an opposed firing pin or igniter,
a stop for the hammer, and means engaging the stop movable during the flight
of the shell to release the same, as described.
3. In a fuse, the combination of a hammer, an opposed firing pin or igniter,
a movable threaded stem, and a movable stop for the hammer released by the
movement of the stem, as described.
4. In a fuse, the combination of a hammer, an opposed firing pin or igniter,
an automatically movable threaded stem, and a movable stop for the hammer
released by the movement of the stem, as described.
5. In a fuse, the combination of a hammer, an opposed firing pin or igniter,
a removable stop for the hammer and a screw-threaded stem engaging a
relatively fixed portion of the fuse and also the stop, as described.
:
6. In a fuse, the combination of a hammer, an opposed firing pin or igniter,
a longitudinally yielding case carrying the same, a stop for the hammer, and a
rotatable device independent of and movable to release the stop, as described.
7. In a fuse, the combination of a hammer, an opposed firing pin or igniter,
a relatively fixed nut and a longitudinally movable nut forming a stop for the
hammer and a screw-threaded stom engaging both of said nuts and movable to
release the movable nut, as described.
8. In a fuse, the combination of the shell, the hammer and a movable firing
pin interposed between the hammer and the side of the shell, whereby owing to
the crushing of the shell and the momentum of the hammer the firing pin is
operated, as set forth.
9. In a fuse, the combination of the shell, the hammer, a quick train and a
time train, a firing pin for the time train, and another firing pin for the quick train
that is operated by the conjoint momentum of the hammer and the indenting of
the shell on striking a substantially solid target, as set forth.
10. In a fuse, the combination of the shell, the hammer, and means for

page_text: exploding the shiell operated by the conjoint momentum of the hammer and the
indenting of the shell on striking a substantially solid target, as set forth.
11. In a fuse, the combination of the shell, independent firing trains, an
igniter for each train, a hammer common to both igniters and operable in the
case of one of the igniters by its conjoint action with that of the crushing in
of the shell, as set forth:
JOHNSONS,
Applicant's Agents, 115, St. Vincent Street, Glasgow.