Improvements in Fuses for Projectiles.
Year: 1899

page_text: Date of Application, 4th July, 1899-Accepted, 2nd Sept., 1899
Improvements in Fuses for Projectiles.
I, HENRY PARKER MERRIAM, Mechanical Engineer, a citizen of the United
States, residing at 136, West 11th Street, New York, in the County and Stato
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;-
This invention relates to improvements in percussion fuses for projectiles, the
object being to simplify and improve the structure and operation of such fuses to
ensure greater safety in handling the projectiles and containty in exploding tho
shell after it strikes the target.
To these ends the invention consists broadly of a fuse body adapted to be secured
in the base of a projectile and formed with a hammer chamber and a bolt cavity,
or socket, a hammer supported in the chamber and having a securing pin or shank
connected with and projecting from it through a suitable opening into the bolt
socket or cavity transversely of the path of movement of the bolt and constructed
and arranged to yield and break under a transverse bending strain, and a bolt
supported in the bolt cavity or socket and exposed to the gas pressure of the pro-
pelling charge of the gun to be forced thereby against the securing pin to bend
the pin laterally and break it off from the hammer to thereby release the hammer
in its chamber. Normally the hammer is supported in inoperative position in
one end of its chamber by the securing pin which is suitably held in the bolt
cavity or socket. The hammer end of the securing pin is held against substantial
lateral movement while the end of the pin in the bolt cavity or socket is exposed
to the transverse bending strain exerted upon it by the bolt when the latter is
forced forward in its cavity by the gas pressure of the propelling charge of the
gun, the securing pin being thereby bent until it breaks adjacent to the hammer.
With such a structure, whereby the pin is broken, by a transverse bending strain,
it is possible to use, with a given force exerted upon the bolt, a much stronger
securing pin that would be possible if the release of the hammer depended upon
the shearing off of the pin by the bolt. This improved structure of fuses therefore
affords greater safety in handling projectiles and insures certainty in releasing
the hammer upon the discharge of the projectile from the gun.
The fundamental principles upon which the operation of the improved structure
depends may be briefly stated as follows: When a rod or pin moves laterally
around a point more or less distant, the velocities of movement of the various
sections of the rod or pin vary proportionaly to the distance of said sections from
the said point.
If the above rod, to be referred to as a first part, be now imagined to be pro-
longed by successive short sections, still keeping one piece of metal, and the
velocity of each of the successive sections of this second part varies gradually from
that of the part of the rod immediately preceding it and proportionally to the
distance of such section from some point not coincident with the centre for the
first part of the rod, then a bending of the rod is produced at the point between
the first and second parts.

page_text: In applying these principles to the breaking of the metal retaining pin or
shank which secures the hammer in inoperative position in a fuse, it will be clear
that if the bending action is confined to a sufficiently short section to overcome
the tensile strength of the material, a rupture of the pin or shank will take place.
The application of these principles to the construction of fuses for projectiles is
claimed broadly in this patent.
In one form of the present invention, the securing pin, (constructed to break
under a transverse bending strain), is suitably connected with the hammer to
normally restrain it from detonating the primers and extends freely through au
enlarged opening from the hammer chamber to the bolt cavity or socket wherein
it is suitably supported and exposed to the action of the hammer releasing bolt
or piston, which, by reason of the arrangement and construction of the pin and
supported hammer in the fuse body, imparts a sufficient transverse bending
strain to the pin to break it and release the humor in its chamber. The pin is
connected with the hammer so as to have a slight rotary movement laterally of the
fuse body, either with the hammer, or independently of the hammer, and is
secured in the bolt socket or cavity either by a connection directly with the bolt
or piston, or by a connection with the fuse body, or by other means which will
allow it lateral movement in the opening between the hammer chamber and bolt
cavity or socket when acted upon by the bolt or piston. When the bolt or piston
is forced forward in its socket or cavity by the pressure of gas of the propelling
charge of the gun, the securing pin will be forced laterally in front of the bolt
or piston; and as the pin must move in a rotary direction around a point at or
adjacent to its hammer end, and when connected directly with the bolt, in a
rectilinear direction at its opposite end or, (when connected with the fuse body
at said opposite end), in a rotary direction around its point of connection with
the fuse body at said opposite end, it will be subjected to an effective transverse
bending strain and will break adjacent to the hammer to release the hammer in
its chamber. The opening communicating between the hammer and bolt cavity
or socket is enlarged to allow free lateral movement of the securing pin in the
fuse body, the pin being confined only by its connection with the hammer and
bolt or fuse body in the bolt cavity or socket. Said opening is preferably an
elongated slot extending in the direction of the bolt cavity or socket. The
securing pin is preferably screw-threaded to render it sensitive to lateral strain
and also to provide a simple and convenient means of attachment to the hammer
and bolt, but the pin may be otherwise connected with the hammer and bolt
(or fuse body) and rendered sensitive to the breaking transverse bending
strain by a cut or groove at the desired breaking section,
In another form of the invention, a hammer supported in the hammer chamber
of the fuse body has a headed securing pin attached to it and extending through
a suitable opening into the bolt cavity or socket, the hammer being supported
in inoperative position in one end of its chamber by the engagement of the pin
head with the wall of the bolt cavity or socket, and a bolt supported freely in
the bolt socket or cavity in engagement with the head of the securing pin and
exposed at its outer end to the gas pressure of the propelling charge of the gun to be
forced thereby against the securing pin head for bending the pin laterally and
breaking off the head from the pin to release the hammer in its chamber.
In this form of fuse the hammer-securing head, which rests in the bolt-cavity
or socket, is preferably spherical, and the bolt is unattached to the head but
rests against the head so that when the bolt is forced forward in its cavity or
socket by the firing of the gun charge, the sphorical head will be forced along the
holt cavity in front of the bolt and transversely of the length of the pin or shank
which secures the head to the hammer, so as to break the head from the pin
and release the hammer in its chamber. The rounded or spherical shape of the
securing-head is important as it affords an effective leverage for breaking off
the head by the movement of tlie bolt.
In the preferred construction of the fuse embodying this invention, the inner

page_text: end of the fuse body is threaded to receive an annular head formed with a
conical or dished inner face in which is seated one or more firing pins and
primers, the primers being in communication with a combustion or firing
chamber in the head in which is supported the charge or charges which explode
and ignite the bursting charge of the shell as hereinafter more fully explained.
The preferred forms of construction of the. improved fuse and their operation
will be hereinafter fully described in detail with reference to the accompanying
drawings, and the novelty will be particularly pointed out in the annexed
claims.
In said drawings,
Figure 1 is a sectional view of a shell representing the preferred form of tho
improved fuse applied thereto, the parts being in the position assumed before
the shell is fired.
Figure 2 is a similar view of the fuse showing the hammer liberated and in
the position assumed when detonating the primers, at the instant of the vleocity of
the shell is suddenly checked; as when striking a target.
Figure 3 is a view similar to Figure 1 showing a slightly modified structure,
the parts being in normal inoperative position.
་
Figure 4 is a detail plan view of the cap containing the quick burning charge.
Figures 5, 6 and 7 are views similar to Figure 1, showing further modified
forms of the improved fuse, the parts being in normal inoperative position in
each case.
Figures 8, 9 and 10 are diagrammatic views illustrating the breaking action
of the hammer securing pin.
Figure 11 is a sectional view of a portion of a shell representing a further
modification of the improved fuse applied thereto, the parts being in the position
tlioy assume before the shell is fired.
Figure 12 is a sectional view of the same form of fuse showing the hammer
liberated and in the position assumed when detonating the primers, at the instant
the velocity of the shell is suddenly checked, as when striking a target.
Figure 13 is a detail view showing the arrangement of the plurality of the
primers or fulminates and their firing pins in this form of fuse.
Figure 14 is a detail plan view of the fuse body shown in Figures 11 and 12,
the primer head or carrier and the hammer being removed to show the peculiar
shape of opening leading from the hammer chamber to the bolt socket or cavity.
Figure 15 is a detail plan view of the delay valve containing the slow burning
or delay charge of explosive.
Figure 16 is a detail plan view of the cap containing the quick-burning charge,
showing a further slight modification.
Figure 17 is a dotail longitudinal sectional view of a further modified form
of my fuse.
Referring first to Figures 1, 2 and 4, the shell 1 is formed in its base with
an interiorly threaded opening into which the body 2 of my improved fuse is
screwed: The fuse body 2 is formed with a hammer-chamber 3 having a hemi-
spherical lower portion 3º in which the spherical hammer 4 normally rests.
6 is the hammer-securing pin or shank, preferably screw threaded from end
to end for the double purpose of making the pin sensitive to à transverse bend-
ing strain and for facilitating the rigid attachment of the pin with the hammer
and bolt. The hammer 4 is formed with a threaded radial opening 5 into which
one end of the threaded pin G is screwed. If desired, the pin 6 may be formed
with a nicked head and extend entirely through the hammer, as indicated in
dotted lines in Figure 1, in which case the head of the pin will confine the
hammer upon the pin and the lower end, only, of the pin need be threaded. The
pin 6 extends from the hammer 4 through an enlarged opening 8 leading from
the hammer chamber into the bolt cavity or socket 7 which is formed in and
extends transversely of the body of the fuse and is open at one end to expose
the firing bolt or piston 9 to the pressure of the gases of the propelling charge of

page_text: the gun. The bolt or piston 9 is formed with a transverse interiorly threaded
opening 10 into which the lower end of the securing pin 6 is screwed. The
opening 10 in the bolt 9 may be directly transverse to the length of the bolt or
it may be inclined more or less to the transverse diameter in the direction of
movement of the bolt, it being preferable to have the opening. slightly inclined
to support the securing pin in inclined position to facilitate the breaking of the
pin, as will be clear from the hereinafter given explanation of the operation.
The opening 8 leading from the chamber to the bolt cavity or socket is con-
siderable larger than the diameter of the securing pin to allow free lateral move-
ment of the securing pin at the moment of firing the shell to facilitate the
breaking of the pin in accordance with this invention. Said opening 8 is-prefer-
ably in the form of an elongated slot extending in the direction of the bolt cavity
or socket. It will be clear from the description as far as gone that in the form
of fuse now being described, the scouring pin is held at its opposite ends in the
hammer and firing bolt while it is free in the opening communicating between
the hammer chamber and bolt cavity or socket. By reason of the spherical
shape of the firing hammer and the hemispherical lower portion of the hammer
chamber, the hammer is capable of only a slight movement in a rotary direction
in the seat of the hammer chamber, while the firing bolt or piston being of
cylindrical shape and supported in a cylindrical bolt cavity or socket is capable
of moving only in a rectilinear direction. The divergent paths of movement of
the hammer and firing bolt having the pin secured to them prevent the various
sections of the pin from moving at velocities proportional to the distance of such
sections from the centre around which the hammer moves, thereby subjecting
the pin to a severe transverse bending strain which results in the breaking of
the pin and the release of the hammer in its chamber.
12 is the usual soft metal gasket or thimble fitting snugly in the open end
of the bolt socket or cavity 7 to prevent the passage of powder gases past the
bolt 9 into the hammer chamber. The bolt or piston 9 is of sufficient length to
shut off communication between the opening 8 and open end of the bolt cavity
'or socket to further ensure against the entry of powder gases to the hammer
chamber.
The inner end of the fuse body 2 is interiorly threaded for the reception of
the annular head or primer carrier 20 which is formed with an annular com-
bustion chamber 22 in which is supported a quick burning charge 23, and a
series of sockets 21 in which are mounted the primers or fulminate patches 24
resting against firing lugs 25. 26 are ball firing pins secured in the sockets 21
in contact with the primers 24. The primers are in direct communication with
the annular combustion chamber 22. The chamber 22 is closed by the circular
perforated plate 30 which is secured in the open end of the annular combustion
chamber by upsetting the metal of the primer carrier 20.
. The inner face of the primer carrying head 20 is dished or formed with a
conical socket in which the ball receiving openings 21 are formed. In the centre
of the conical socket is formed a cylindrical recess in which rests a small conical
spring 50 which is adapted to engage the hammer 4 for steadying it and prevent-
ing its knocking against its casing during flight, and insuring a maximum force
of impact of the hammer against the primers when the shell strikes the target.
When the velocity of the shell, after firing, is retarded, as when striking a
target, the spring 50 is easily compressed by the hammer and does not appreciably
interfere with the detonation of the primers.
Referring to Figure 3 of the drawing, it will be observed that the hammer
securing pin 6 is secured to the hammer and firing bolt as in the form shown in
Figures 1 and 2 but in this modified form the securing pin is inclined to a greater
degree to increase the transverse bending strain exerted upon the securing pin
when the projectile is fired.
In the modified form shown in Figure 3 the structure of the primer carrier is
also somewhat different from the preferred form above described. In this form

page_text: is employed a single primer 35 mounted in a central socket in the primer head 20
and communicating with the annular combustion chamber 22 through one or
more inclined passages 36. A single ball firing pin is mounted in, the central
socket of the primer head in contact with the primer. The conical spring 50
of the preferred form of fuse is omitted and in its place a spider-shaped spring 38
is substituted for engaging and steadying the hammer in its chamber during
flight of the shell.
In the form of fuse shown in Figure 5, the hammer securing pin or shank
is integral with or otherwise rigidly attached to the spherical hammer 4" and
projects radially from the hammer through enlarged opening 8 into bolt cavity
or socket 7 and secured at its lower end in the wall of the bolt cavity or socket,
preferably by a threaded engagement therewith. The pin has an annular out
or groove 6 between its ends and is engaged at or adjacent to the cut or grooved
section by the bolt or piston 9 which has a vertically beveled forward end. The
hammer chamber is formed the same as in the form shown in Figure 1, to allow
a slight rotary movement of the hammer therein. When the bolt is forced
forward in its cavity, the central reduced section of the securing pin or shank will
be forced laterally in front of the bolt, the transverse sections of the pin on
either side of the reduced section moving proportionally to their distance from
two points (the centre around which the hammer turns and the point of attach-
ment of the lower end of the pin with the fuse body in the bolt cavity or socket)
producing a transverse bending strain which is concentrated at the reduced
section of the pin, causing the pin' to break at said section to release the hammer
in its chamber. The structure shown in Figure 5 is designed to operate with
a primer head such as shown in either Figure 1 or Figure 3.
In Figure 6 the hammer chamber 3 is of cylindrical shape having the slot or
opening 8 leading to the bolt-cavity or socket. The hammer 4 is of approximate
pear-shape with its enlarged impact end fitting the hammer chamber and its
reduced end resting loosely in the end of the hammer chamber adjacent to the
bolt cavity or socket and free to move laterally. A headed securing pin passes
through an axial opening in the hammer and is screwed into the bolt or piston 9
whereby it is supported to retain the hammer in inoperative position in its
chamber. The hammer has an impact head 4 and is adapted to operate with a
primer head having a single centrally located primer, such as in Figure 3. In
this form of fuse the action of breaking the securing pin is the same as with the
forms shown in Figures 1, 2 and 3, the hammer moving in a rotary direction.
when the bolt moves in a rectilineal direction.
In Figure 7 the fuse body is of the same construction as in Figure 6, but the
hammer is of cylindrical shape loosely fitting the hammer chamber and formed
with an axial opening 4ª which flares or enlarges toward the bolt end. A
headed securing pin 6 passes through the flaring opening 4° and is screwed into
the bolt 9. The head of the pin engages an internal shoulder 4d in opening 4°
for confining the hammer. A firing pin 4° is attached to the head of the hammer
in position to detonate the primer supported in a primer head in any suitable
manner. In this form of the fuse, the firing pin ball is omitted from the primer
head to allow firing pin 4° to detonate the primer. In this form of fuse the pin
is capable of a slight movement in a rotary direction independently of the hammer
which cannot move laterally, the flaring axial opening in the hammer allowing
the movement of the pin.
:
In Figure 9 is represented diagrammatically the successive positions of the
parting sections of the securing pin during the breaking action in the forms of,
fuses shown in Figures 1. and 3. a indicates the portion of pin moving with,
the hammer in a rotary direction, while 6 indicates the portion of pin moving
rectilineally with the bolt or piston. c is the point of rupture due to the bending
strain.
In Figure 8 is shown in a similar manner the breaking action of the pin in the
form of fuse shown in Figure 5, in which the sections upon either side of a reduced

page_text: section move proportional to their distance from two points, the centre of rotation
of the hammer and the point of attachment of the lower end of the pin with the
fuse body. a and b indicate the parting portions and e the section of rupture.
In Figure 10 is shown the breaking action in the forms of fuse shown in
Figures 6 and 7, which is very similar to the action illustrated in Figure 9.
The operation of the improved fuse as shown in Figures 1, 2 and 3' and 4 will
now be described.
The fuse being applied to the projectile with the parts in the position shown
in Figure 1, the projectile is fired from the gun. The pressure of the exploded
propelling charge of the gun which expels the projectile therefrom, forces the
bolt or piston 9 longitudinally in its socket or cavity 7, the bolt or piston
travelling rectilineally and tending to carry the securing pin and connected
hammer in the same direction, causing the hammer to rotate slightly in the
hemispherical seat 3 in the lower part of the hammer chamber, the result being
the application of an effective transverse bending strain upon the securing pin
between the bolt and hammer which breaks the pin at this point and releases
the hammer in its chamber. The effectiveness of the transverse breaking strain
upon the securing pin is due to the divergent paths of movement of the bolt and
hammer which prevents the various transverse sections of the securing pin from
moving at velocities proportional to their distance from the centre around which
the hammer moves.
During the flight of the projectile the hammer 4 rests under the force of the
spring 50 or 38 in the hemispherical recess 3 of the hammer chamber. As
soon as the projectile strikes the target its velocity will be suddenly checked and
the hammer 4 will be forced to the inner end of its chamber, compressing the
retaining spring and striking one or more of the firing pin balls. The percussion
of hammer 4 against one of the firing pin balls detonates one or more of the
primers and the flash from the primers passes into the combustion chamber 22,
ignites the quick burning charge therein and the flash from said charge com-
municates with the bursting charge of the projectile.
Referring now to Figures 11 to 16 of the drawings, a further modification of
the improved fuse will be explained, only those features differing from the here-
inbefore referred to forms being specifically described. The hammer 4 resting
in hammer chamber 3 as described; is provided with a spherical retaining head 4*
attached to it by a reduced shank or pin 6. The hammer 4, head 4* and shank
or pin 63 are preferably turned out in an integral piece, but the head and shank
may be separately formed and secured to the hammer in any suitable manner.
is the bolt-cavity or socket formed in and extending transversely of the
body of the fuse and open at one end to expose the firing bolt or piston to the
pressure of the gases of the propelling charge of the gun. 8 is an inclined
circular opening leading from the lower portion 3* of hammer-chamber 3 into the
bolt-cavity 7, and 8 is a semicircular notch formed in the inner wall of open-
ing 8, the notch 8 being in the central longitudinal line of the fuse body and
the enlarged opening or passage 8 being to one side of said central line, and the
opening 8 and notch 8 forming a locking eyelet for the hammer-retaining
head 4 as hereinafter explained. 9 is the cylindrical bolt or piston resting.
freely in the bolt socket or cavity 7 and confined against the head 4 by means
of a pin 9 passing transversely across the outer end of socket 7 and seated in
the walls of the socket. In locking the hammer 4 in place, the head 4* is passed
through opening 8 into bolt-cavity 7 and the hammer 4 is rotated slightly in
its seat 3 to bring the pin 6 into the notch 8 and the head 4 in the bolt socket.
The bolt 9 is then slipped into its socket against head 4* and secured by pin 9*.
The bolt or piston 9 has its outer end bored out slightly to form
an annular flange 9 which can be expanded into close contact with
wall of bolt socket or cavity 7 to prevent the passage of powder gases past the.
bolt 9 into the hammer-chamber. If preferred the usual soft metal gasket or
thimble may be employed to prevent the passage of powder gases. The bolt or-

page_text: piston 9 is of sufficient length to shut off communication between opening 8' and
open end of socket 7 whether the bolt is in its normal outer position or its inner
position, which is assumed after firing.
In Figure 17 is illustrated a modified form of the hammer securing and releas-
ing device just described. In this form of the device the hammer and retaining
pin and head are the same as in the form shown in Figures 11 and 12. The bolt
cavity or socket 7 is however bored through from side to side of the fuse body
and is reamed out to a larger diameter for one-half of its length to receive a
tubular plug having a solid threaded head 7 which is threaded into the
enlarged bore of the bolt cavity. The bore of the tubular plug 7 is of the same
diameter as the bolt socket or cavity 7, forming a continuation thereof for the
purpose hereinafter explained. The locking eyelet 8, 8 communicating between
the hammer chamber 3 and bolt cavity 7 is, in this modified form of the device,
arranged to communicate with the enlarged bore of the bolt cavity farthest away
from the open end thereof, so that when the hammer retaining bead 4* is passed
through opening 8* into the bolt cavity and the tubular plug 7 is put in place,
the inner edge of the plug will engage the pin 6 and hold it snugly in place in
the notch 8, the head 4 engaging the inner wall of the bolt cavity and inner
wall of the plug for firmly supporting the hammer in its seat 3".
In these forms of the fuse, the primer carrier 20 is provided with a series of
passages 21 leading from the hammer chamber 3 to the combustion chamber 22,
as well as the fulminate patches 24, firing lugs 25, and ball firing pins 20
described with reference to Figure 1 of the drawings.
31 is a cylindrical controller or delay valve formed with a contral stem 32
which rests in the central cylindrical socket 20 formed in the head 20. The
valve 31 rests normally upon the central annular flange 20 of the head 20. Tho
controller valve 31 has radial cuts or notches 31ª, and packed tightly within
the recess in the face of the valve. and in the cuts or notches 31 is the delay
burning charge 33 of any suitable material. It will be observed that the radial
cuts or notches 31° expose small parts of the tightly packed charge 33 at the edge
of the valve within the combustion chamber 22.
40 is a hollow plug or cap threaded into the upper end of the head 20, the
plug or cap 40 having a chamber 40" within which is packed the quick burning
charge 41. The chamber 40 has a central opening 40 which forms a com-
munication between the combustion chamber 22 and the quick burning charge 41.
In Figure 11, 41ª is a dished disk of very thin celluloid placed in cap 40 beneath
the charge 41 to prevent the loosely packed charge sifting through opening 40b
into the combustion chamber 22. The flash from the delay charge 33 readily
pierces the celluloid 41" for igniting charge 41. In Figure 12, is shown a wad of
gun-cotton 41 serving the same purpose as disk 41° of celluloid. The chamber 40"
is closed by a disk 43 which rests upon a flange or shoulder in the chamber and
is secured by upsetting the surrounding metal of the plug or cap 40 upon the
disk. The upset. portion is indicated at 44. The disk 43 is blown off by the
charge 41 to fire the shell bursting charge. As shown in Figure 16, the disk 43
may be formed with a number of perforations 43" to allow the flash of charge 41
to pass into the bursting charge of the shell without necessarily blowing, off the
disk 43.
The parts of the improved fuse shown in Figures 11 to 16 aro assembled as
follows;
The hammer 4 and the attached pin 6 and head 4 are placed in the hammer-.
chamber 3 of the fuse-body and inclined slightly, and in this position the head 4*
in passed through opening 8. The hammer and attached parts are then rotated
slightly, the hammer moving in its scat 3ª, to bring head 43 in proper position
in bolt-socket 7 and pin 6 in the notch 8. The bolt 9 is then placed in its socket
against the head 4* and the pin 9 or other equivalent device is secured in place.
The bolt 9 lolds the head in position and prevents its sidewise movement toward
opening 8*, the head engaging the wall of the socket to support the hammer. 4.

page_text: in its seat 3. The hammer end of the securing pin is held against lateral move-
ment, while the headed end of the securing pin in the bolt cavity or socket is
in position to be exposed to a transverse strain exerted upon it by the bolt when
the latter is forced forward in its cavity by the gas pressure of the propelling
charge of the gun. This transverse strain upon the securing pin breaks it to
free the hammer. The head 20 with its attached parts is screwed in place in tho
fuse body, when the fuse is ready to be applied to the shell.
In the modified form shown in Figure 17, the tubular plug being removed, the
hammer 4 is put in place in the fuse body with the head 4* in the bolt-socket
as above explained, and the tubular plug is then screwed into position in the
threaded enlarged end of the bolt-socket, engaging the pin 6* of the head 4*
to hold the parts in position. In this form of the device the bolt 9 rests against
the lead 4 on the opposite side from plug 7, and need not be secured, as in
the preferred form.
This fuse being applied to the projectile with the parts as shown in Figure 11, 1
the projectile is fired from the gun. The pressure of the exploded propelling
charge of the gun which expels the projectile, forces the bolt or piston 9 longi-
tudinally in its socket or cavity 7, the inner end of the bolt or piston engaging
the spherical head 4* of the hammer retaining pin 6 and forcing it along the
socket or cavity 7, straining and bending the pin 6 laterally, causing it to break 2
and freeing the hammer 4, as shown in Figure 12. The engagement of the plane
surface of the inner end of the bolt or piston 9 with the curved face of the
spherical head 4 affords ample leverage for readily breaking the pin 6, the
head tending to roll against the surface of socket 7 to assist in the breaking
action. During the flight of the projectile the valve 31 carrying slow burning 2
charge 33 rests in the position shown in Figure 11, but when the projectile
strikes the target the valve 31 is forced against the inner face of the cap or
plug 40. The other parts of the fuse operate the same as already described with
reference to Figures 1, 2, 3 and 4.
.
The percussion of hammer 4 against one or more of the firing pin balls 26
detonates one or more of the primers 24 and the flash from the primers passes
into the combustion chamber 22 and ignites the delay charge 33 at the edges,
the surface of the delay charge 33 being entirely covered by cap 40 and only the
small portions of said charge in the cuts or notches 31" being exposed. The
delay charge 33 gives the shell time to pierce the target. During the penetration
of the target the valve 31 is firmly held against cap 40, by reason of the violent
checking of the velocity, but immediately after the retardation of the shell has
ceased the pressure of the gas generated between the surfaces by the burning
delay charge forces the valve back against the annular seat 20". As soon as
the valve 31 is returned to. seat 20° the fire reaches over the unburned surface
of the delay charge and passes to the centre of the quick burning charge 41
piercing the celluloid 41 or igniting the gun-cotton 41 and exploding the
charge 41, blowing out the disk 43, (or Hashing through perforations 43°)
and igniting the bursting charge of the projectile.
The operation of the modified form shown in Figure 17 is practically the same 4
as just described. The bolt 9 engaging head 4* breaks the head from the pin 6,
the pin being supported by the engagement of the tubular plug 7* and the head
being forced into the bore of the plug.
It will be observed that in both forms of the fuse illustrated in Figures 11-17,
the locking eyelet or opening which communicates between the hammer-chamber t
and bolt-cavity or socket comprises an enlarged hole or opening 8 extending
through the bottom of seat 3 at one side of the central longitudinal line of the
fuse body, and a contracted portion or notch 8 extending through the bottom
of seat 3 in the central longitudinal line of the fuse body. The enlarged portion
of the eyelet or opening permits the passage of the round hammer retaining head 5
into the bolt cavity, and the contracted portion, or notch, receives the pin or
shank of the head. In both forms means must be provided for holding the head

page_text: against accidental sidewise movement toward the enlarged part 8 of the eyelet
or opening. In the preferred form of the device the bolt 9 holds the head in
locked position, while in the modified form the tubular plug holds the head in
position.
The principal useful' and desirable result derived from the improved arrange-
ments is the greatest possible safety with a given force available for releasing
the hammer, whereby the hammer can be more effectively secured against
accidental release previous to the firing of the shell. It is evident that the
limitation of the force holding the hammer in its seat in the fuse body in the
direct tensile strength of the smallest cross section of the retaining pin or shank,
and the strain, set up by accidental shocks to which the fuse is subjected previous
to firing, which would tend to release the hammer in its chamber, would almost
entirely be that of direct tension upon the pin or shank, while the force necessary
to the release of the hammer in its chamber is a transverse bending force con-
trollable by a sharp groove or thread cut in a single short section of the pin or
shank. The disparity between these two forces can be readily shown by taking
a small metal rod, preferably steel, having a sharp circumferential groove cut
into it at a point midway of its length. To break this grooved rod by a transverse
bending strain concentrated at the reduced section would require only a small
fraction of the force necessary to disrupt the rod by direct tension or shearing.
By the expression used in the specification and claims, "the securing pin or
shank connected with the hammer" it is intended to cover any and all means of
connecting or joining the securing pin or shank and hammer, whether the pin or
shank is screwed into the hammer or is formed integral with the hammer, or
passes loosely through the hammer and confines the hammer upon it by means
of a head or enlargement or other confining means, or any other connection
whereby the hammer is supported in its chamber by the pin or shank.
It is to be understood that this invention is broadly distinguishable from those
fuses in which the hammer is released by directly shearing or cutting off its
securing pin between the co-acting surfaces of the bolt and wall of the bolt cavity
in that in this invention the securing pin is subjected to a transverse bending
strain by the forward movement of the bolt to break the pin and release the
hammer. It is believed that the present invention is the first instance of breaking
the securing pin by a bending strain to release the hammer, as distinguished from
shearing or cutting off the pin to release the hammer.
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 percussion fuse for projectiles, the combination of a fuse body having
a hammer chamber and a bolt socket or cavity, a hammer in said chamber having
a securing pin attached to it and extending into and held within said bolt
cavity or socket to support the hammer, said securing pin being constructed and
arranged to yield and break under transverse bending strain, and a bolt or
piston supported in said bolt cavity or socket so as to be exposed to the gas
pressure of the propelling charge of the gun and adapted to be forced forwardly
in its socket thereby, to strain the securing pin laterally and bend and break
the same for releasing the hammer in its chamber, substantially as set forth.
2. In a percussion fuse for projectiles, the combination of a fuse body having
a hammer chamber and a bolt socket or cavity, a hammer in said chamber
having a securing pin attached to it and extending into and held within said bolt
cavity or socket to support the hammer, said securing pin being held at the
hammer end against substantial lateral movement while its other end is capable
of lateral movement to effect the bending and breaking of the pin, and a bolt or
piston supported in said bolt cavity or socket so as to be exposed to the gas
pressure of the propelling charge of the gun and adapted to be forced forwardly

page_text: in its socket thereby, to strain the securing pin laterally and bend and break the
same for releasing the hammer in its chamber, substantially as set forth.
.
3. In a fuse for projectiles, the combination of a fuse body having a hammor
chamber and a communicating bolt cavity or socket, a hammer supported in its
chamber, a bolt or piston supported in the bolt cavity or socket and arranged to
be exposed to the gas pressure, of the propelling charge of the gun, and a
hammer securing pin, sensitive to lateral bending strain, and connected with the
hammer and held in the bolt cavity or socket; the hammer, the bolt and the
hammer-securing pin being constructed and arranged to cause one. portion.of
the pin to move in a lateral rotary direction with relation to a point more or,
less distant and restrain another portion of the pin from moving proportionally
to the distance from said point, whereby the pin will be subjected to a breaking
transverse bending strain, substantially as set forth.
4. In a fuse for projectiles, the combination of a fuse body having a hammer
chamber and a communicating bolt cavity or socket, a hammer supported in its
chamber, a bolt or piston supported in the bolt cavity or socket and arranged to
be exposed to the gas pressure of the propelling charge of the gun, and a.
hammer securing pin connected with the hammer and bolt and sensitive to
lateral bending strain; a portion of the hammer securing pin being adapted to
move in a lateral rotary direction with regard to a point more or less distant,
and another portion of the pin being adapted to move in a divergent path
disproportionately to its distance from said point, whereby the pin is subjected
to a breaking bending strain, substantially as set forth.
5. In a fuse for projectiles, the combination of a fuse body having a hammer
chamber and a communicating bolt cavity or socket, a hammer supported in
its chamber, a bolt or piston supported in the bolt cavity or socket and arranged
to be exposed to the gas pressure of the propelling charge of the gun, and a
hammer securing pin connected with the hammer and bolt and sensitive to
lateral bending strain; the hammer and bolt being arranged to move in
divergent paths or directions when the bolt is forced forward in its cavity or
socket, by the gas pressure of the propelling charge of the gun, substantially
as set forth.
6: In a fuse for, projectiles, the combination of a fuse body 'having a hammer
chamber and a communicating bolt cavity or socket, a hammer supported in its
chamber, a bolt or piston supported in the bolt cavity or socket and arranged
to be exposed to the gas pressure of the propelling charge of the gun,, and a
hamnier securing pin connected with the hammer and bolt and sensitive to lateral
bending strain, and passing freely through the opening communicating. between
the hammer chamber and bolt cavity or socket, the bolt being capable of moving
rectilineally under the gas pressure of the propelling charge of the gunwhile
the hammer is capable of moving only in a rotary direction under the action
of the bolt exerted through the securing pin, substantially as and for the purpose
set forth..;
7. In a fuse for projectiles, the combination of the fuse body having a hammer
chamber and a bolt cavity or socket, a hammer in the hammer chamber, a bolt in
the bolt cavity or socket arranged to be exposed to the gas pressure of the
propelling charge of the gun, and a hammer securing pin, sensitive to lateral
bending strain, connected at its opposite ends with the hammer and bolt and
passing freely through an opening communicating between the hammer chamber
and bolt cavity or socket and inclined to the transverse diameter of the bolt,
substantially as set, forth.
14
8. In a fuse for projectiles, the combination of the fuse body having a hammer
chamber formed with an approximately hemispherical lower end and a bolt
cavity or socket extending transversely of the hammer chamber and communicating
therewith through a slot or elongated opening extending in the direction of
length of the bolt cavity. or socket, a spherical, hammer supported in the hammer
chamber, a bolt or piston in the bolt cavity or socket, and a hammer securing

page_text: pin sensitive to transverse bending strain secured at its opposite ends to the
hammer and bolt and extending through the slot or elongated opening, sub-
stantially as set forth..
9. In a fuse for projectiles, the combination of a fuse body having a hammer
chamber and a bolt cavity or socket communicating through an enlarged opening,
a spherical hammer in its chamber having a limited rotary movement and confined
against direct lateral movement by its engagement with the wall of the hammer
chamber, a bolt in its cavity or socket having a rectilinear movement, and a
securing pin sensitive to transverse bending strain and connected at its ends
with the hammer and bolt, whereby, when the bolt is forced forward in its
cavity or socket by the firing of the projectile from the gun, the hammer moving
only in a rotary direction and the bolt moving only in a lineal direction, the
hammer securing pin will be strained and bent laterally until it breaks to free the
hammer in its chamber, substantially as set forth.
10. In a fuse for projectiles, the combination of a fuse body having a hammer
chamber and a communicating bolt cavity or socket, a hammer supported in
its chamber, a bolt or piston supported in the bolt cavity or socket and arranged
to be exposed to the gas pressure of the propelling charge of the gun, and a
hammer securing pin connected with and extending radially from the hammer
and rigidly attached to and extending in a transversely inclined direction from
the bolt, said pin being sensitive to lateral bending strain; the hammer and
bolt being arranged to move in divergent paths or directions when the bolt is
forced forward in its cavity or socket by the gas pressure of the propelling charge
of the gun, substantially as set forth.
11. A percussion fuse for projectiles comprising a fuse-body having a hammer-
chamber and a bolt-cavity or socket, a hammer having a securing head attached
to it and resting in the bolt-cavity or socket, said head engaging the wall of
the bolt-cavity or socket and supporting the hammer in inoperative position in
its chamber, and a bolt or piston freely supported in the bolt-cavity or socket in
position to be exposed to the gas pressure of the propelling charge of the gun,
and adapted to be forced thereby against the securing head to break the head
from the hammer and free the hammer in its chamber, substantially as and for
the purpose set forth.
12. A percussion fuse for projectiles comprising a fuse-body having a hammer-
chamber and a bolt-socket-cavity, a hammer in the chamber, a pin secured to the
hammer passing through an opening between the hammer chamber and bolt-
cavity or socket and provided with a rounded head which rests in the bolt-
cavity or socket and by its engagement therewith supports the hammer in its
chamber, and a bolt or piston supported in the bolt-cavity or socket in position
to be exposed to the pressure of gas of the propelling charge of the gun and
adapted to be forced against the rounded head for breaking the pin and releasing
the hammer, substantially as set forth.
13. A percussion fuse for projectiles comprising a fuse-body having a hammer
chamber and a bolt-cavity or socket communicating with the hammer chamber
through a locking eyelet or opening having an enlarged part and a contracted part
or notch, a hammer in the hammer-chamber, a rounded bead having its più or
shank secured to the hammer, the head' being adapted to be passed through the
enlarged part of the locking eyelet into the bolt-cavity or socket and the pin or
shank to engage in the contracted part or notch of the eyelet, and a bolt or
piston freely supported in the bolt-cavity or socket in position to be exposed to
the gas pressure of the propelling charge of the gun and adapted to engage the
rounded head and force it to one side to break the pin and release the hammer,
substantially as set forth.
14. A percussion fuse for projectiles comprising a fuse-body having a hammer
chamber and a bolt cavity or socket communicating with the hammer-chamber
through a locking eyelet or opening having an enlarged part and a contracted
part or notch, a hammer in the hammer chamber, a rounded head having its

page_text: pin or shank secured to the hammer, the head being adapted to be passed
through the enlarged part of the locking eyelet into the bolt-cavity or socket
and the pin or shank to engage in the contracted part or notch of the eyelet,
a bolt or piston supported in the bolt-cavity or socket in engagement with the
rounded head and exposed to the gas pressure of the propelling charge of the
gun, and a device retaining the bolt in its socket, substantially as set forth.
D
P T 1
1000
JOHNSONS,
Applicant's Agents, 115, St. Vincent Street, Glasgow,