Improvements in Fuzes.
Year: 1892

page_text: Date of Application, 1st Mar., 1892-Accepted, 4th June, 1892
COMPLETE SPECIFICATION.
Improvements in Fuzes.
I, HENRY PARKER MERRIAM, of 11 Charlton Street, New York, United
States of America, Engineer, 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 percussion fuzes for explosive shells designed for use at
the base or front of such shells.
The improved fuze consists essentially of a ball, or other form of hammer,
mounted loosely in position to strike the cap by the impact of the shell against the
target, a holder or stop normally holding the hammer a distance from the cap, and
a coacting trip which upon the firing of the shell moves or releases the stop so that
the hammer may strike the cap or caps at the moment of impact; as will be fully
hereinafter set forth..
Referring to one form of the invention :
Figure 1, (Sheet 1) is a central sectional elevation of the fuze, the shell being
indicated by dotted lines.
Figs. 2 and 3 (Sheet 1) are cross sections on the line 2, of Fig. 1, looking in
opposite directions.
Fig. 4 (Sheet 1) is a detailed view of the stop.
Fig. 5, (Sheet 2) is a view similar to Fig. 1, illustrating a modified form.
Fig. 6, (heet 2) is a detail of a further modification, and
Fig. 7, (Sheet 2) a central section showing the employment of a plurality of
impact hammers.
Referring to Figs. 1 to 4, (Sheet 1) the shell A with which the invention is
combined may be of any approved form making use of an explosive bursting
charge.
The improved fuze is contained by a hollow stud 20 having at one end an
exterior threaded portion 21 for screwing into the base of the shell and at the
opposite end a polygonal head 22 for a wrench. The stud provides a central
pocket 23 to contain a ball 24 or other form of hammer, which pocket at its outer
end has a screw threaded portion 19 for an annular head 18 thus removably con-
nected with the stud. The hammer is smaller than the pocket, and the rear
wall 9 of the latter is shaped to fit a portion of the hammer's surface and thus aid
in holding it centrally therein. The inner side of the head 18 is concaved and has
a central perforation screw threaded to receive a similarly threaded adjusting
pin 8.
In front of this perforation the head has an enlarged outer recess 7 that is
also screw threaded to receive a centrally perforated nipple 17 the outer end of
which projects inwardly toward the centre of the shell. The concaved side of the
head 18 is provided with one or more seats 6, three are shown, radially disposed
therein with respect to such concavity or to that of the ball, in each of which is
seated a percussion cap 5, the rear of each of the caps from the seats 6, being open
by ducts 4 with the recess 7 and by the perforated nipple with the powder in the
body of the shell.
The hammer 24 is held in its normal position against the rear wall of the fuze
pocket by means of a withdrawing, removable or releasable stop 3 formed by the
end of a bolt 16; said holt being interposed between the hammer and the
concaved end of the head 18 so as to normally prevent said ball from coming in
contact therewith.
In the preferred form, the bolt 16 is split longitudinally for the greater portion
of its length to provide a plurality of spring or yielding arms, the tendency of
which is to spring outwardly. Coacting with this bolt is a trip or tripping sleeve 15.

page_text: which surrounds the bolt for the greater portion of its length, and in the norma
position of the parts permitting the spring arms to extend outwardly freely, but a
the sleeve is slid rearwardly over the bolt compresses said arms together t
decrease the effective diameter of the rear end of the bolt, thereby withdrawing
removing or releasing its stop,3,, as will, presently appear. The stop bolt has its
front end seated in the perforation of the centre of the head 18 abutting against
the adjusting pin 8, and the ball is counterbored to provide a deep recess whiel
intermediate of its.length is reduced in.diameter to provide an internal shoulder 2
against which the stop end of the bolt bears, whereby the hammer is held against
the rear wall of the pocket or is prevented from striking the caps. The sleeve 15
is interposed between the concaved end of the head and the stop end of the bolt
and projects with the bolt into the recess in the hammer. The construction and
operation of these parts are such that at the moment of the propulsion of the shell
the sleeve will slide along the bolt with sufficient force to compress its spring arms,
to remove the stops formed thereby from the shoulder 2 of the hammer, and sliding
together with the bolt further into the hammer, permits the latter to move at the
moment of impact, by the force due to its inertia, forward into forcible contact
with one or the other of the caps exploding it, and the flame through the ducts
and perforations, before referred to, ignites the powder within the body of the
shell.
The seats 6; sustaining the caps are preferably although not essentially, recessed,
deep enough to receive a firing pin 1, which is thus interposed between the cap and
the hammer and serves as a further means of ensuring the explosion of the cap,
and these balls are held in place by burnishing down the edge of the recess
confining the balls against the cap. The hammer 24 may independent of the stop
bolt be held to its seat in the pocket and steadied by a spring consisting of an
annulus 14 fitting the end of, the pocket. 23 with a number of radial spring arms 13,
extending slightly forward so as to bear upon the hammer in proximity to the
sleeve 15, and tending also to hold the hammer against the rear of the pocket after
the withdrawal of the stop.
The sent 6. for the cap has a central projection at its base presenting an edge to
the inner side of the cap to better ensure its being fired by the hammer; and the
adjusting pin 8 ensures the stop end of the bolt 16 resting snugly against the
shoulder 2 with the hammer firmly seated against the rear wall of the pocket.
The nipple 17 is preferably a removable one containing a slow or quick burning
fuze of the ordinary form, the nipples being removable so that one may be replaced
by another of a different length or containing a different fuze. The ducts 4 aud
space 7 will also contain, some of the powder of the fuze; and in case the fuze is a
slow burning one,. the resulting gases may pass by a vent 10 through the head into
the pocket 23.
In the modification, Fig. 5, (Sheet 2) the hammer 24 is shown solid; and the
stop pin and its co-operating sleeve are contained by a thimble 25 screw threaded
into the front end of the head 18 and opening inwardly into the pocket 23. The
rear end of the thimble 25 forms a shoulder 26 against which a stop formed on
the stop pin 16 abuts. The stop pin is split as before to provide spring or yielding
arms and the stop 3 instead of being formed as in Fig. 1 at the end of the spring
arms is, formed intermediate of their lengths; the rear end of the arms extending
into the pocket 23 to form an abutment for the hammer, normally holding it to its
seat against the rear wall of the pocket and preventing it from moving against the
caps. The sleeve 15, as before, surrounds the stop bolt 16 and normally lies
against the closed end of the thimble 25 so that in its rearward movement it will,
as before, compress the spring arms of the bolt together, thereby withdrawing the
stop formed by the bolt from the shoulder 26 and thus freeing the stop bolt. and at
the retardation of the shell at the moment of impact whether head or side on, the
hammer continuing its motion unchecked for the instant will strike the caps, or
either of them, and explode the shell; the same force moving the hammer forward,
also simultaneously moves the. bolt and, sleeve forward further into. the thimble 25.

page_text: In this construction also, the cap seats 6, open into a front recess 11 in the head 18
which may contain a fuze if desired.
In the modification Fig. 6, (Sheet 2) the bolt 16 instead of its spring arms
tending to spring outwardly and positively compressed together by the trip to
remove the stop from the shoulder, is reversed; that is, its spring arms have a
tendency to spring inwardly and are forced and held normally outward by the head
of an interior tripping pin 27 which in the act of firing moves from between the
inner end of the spring arms of the bolt 16, thereby allowing said bolt to move
inwardly decreasing the effective diameter of the bolt and withdrawing its stop
end 3 from the shoulder 2 of the hammer, thus freeing the ball and allowing it to
move forward as before.
In order to augment the effective force of the hammer upon the cap or caps, or
to render a fuze of smaller diameter more effective, the pocket 23 may be elongated
so as to contain two or more balls arranged in axial alignment with respect to the
axis of the fuze, as shown in Fig. 7 (Sheet 2). In this instance the balls need not
be so large in proportion as shown in the previous figures but may be somewhat
smaller and held together, with the rear haimmer bearing against the rear wall of
the pocket by the spring 13 and supported by a surrounding series of small balls
arranged between their respective contiguous surfaces to prevent it from normally
lying against the side walls of the pocket. Upon the impact of the shell against
the target, the combined inertia of the hammers together with any lateral displace-
ment forces the forward hammer against the cap or caps.
In the second form of the invention the retainer or step for the hammer is
tripped by a plunger or plungers moved by the pressure of the propelling charge
in firing the shell from the gun as shown in Sheet III in which:
Figure 1 (Sheet 3) is a longitudinal sectional elevation; Fig. 2, (Sheet 3) is a
rear elevation thereof; Fig. 3, (Sheet 3) represents by a face and side elevation
one of the retainers. Figs. 4 and 5, (Sheet 3) are views similar to Fig. 1, (Sheet 3)
illustrating modified forms of the invention.
Referring to said Sheet III the fuze is represented as arranged at the base of a
shell A, partially indicated by dotted lines, and the fuze B in the main consists of
a fuze-case b, which contains a percussion hammer c, a seat or seats for a cap e, and
an igniting charge i.
The fuze-case is composed essentially of two portions 10, 11, united by screw
threads, the portion 10 having exterior threads 12 for securing into the opening in
the base of the shell and its rear or head 13 squared as in Fig. 2, to facilitate the
use of a wrench in screwing the fuze in place.
The portion 10 is centrally recessed from the front to provide a chamber 14 for
the percussion hammer, and the rear wall of the chamber is shaped to conform
with and receive a portion of the hammer which will confine the hammer to a
central position in the chamber independent of any similar function of the retainer
or retainers to be hereinafter explained, and also in aid of their proper action.
The hammer chamber is closed by the other portion 11 of the fuze-case which is
formed with one or more radial openings 2, in which is seated the cap e, each
opening being in communication by an inclined passage 3 with a central front
recess 15 containing the igniting charge. The openings 2 to the cap seats, (which
otherwise might be formed by nipples extending into the hammer chamber) each
preferably contain a firing pin 1, in the form of a sphere which projecting
partially into the hammer-chamber are readily struck by the hammer in its
percussion movement.
The hammer c, is held to its seat or against the rear wall of the chamber by one
or more retainers a, shown in Fig. 1, (Sheet 3) and in detail in Fig. 3, (Sheet 3)
as consisting of a strip adapted to be interposed between a shoulder on the fuze-
case and a shoulder 2 on the percussion hammer. The retainer trip in the form
shown in Fig. 1, (Sheet 3) is duplicated one on each side of the hammer and is
formed with two diverging spring fingers a', and a central finger a²; the fingers lie
in a circumferential recess in the hammer and against the shoulder formed thereby,

page_text: and act as separated struts, the two spring fingers a having sufficient elasticity to
secure and guard the retainer against accidental displacement when the fuze is
subjected to jar in ordinary handling. The shoulder on the fuze-case may be
formed by a projection from either the portions 10 or 11 thereof, but is preferably
provided by an adjustable annulus 4 screwed into the other portion 10 immediately
ahead of the portion 11. Each of the retainer strips a, is provided with a tit or
projection 5 that extends partially into a perforation 6, thereby holding the
'retainer from slipping out of place, and also extends in the path of a movable
trip in, and tends to oppose its movement, for a purpose to be described.
The head
The movable trips m, are arranged at diametrically opposite points and longi-
tudinally in the portion 10 of the fuse-case; and each consists, as shown in Fig. 1,
(Sheet 3) of a pin having an enlarged head 7 fitting an enlargement of the per-
foration, said enlargement opening outward to the rear of the fuse-case.
of the trip is provided with a packing disc to prevent the escape of pressure past
the head and to protect the trip and prevent it from accidentally falling out of
place, the rear opening of the perforation is guarded by a perforated disc 8.
The structure so far described is such that at the moment of firing the shell with
the improved fuze, the pressure produced in firing enters the openings in the rear
of the fuze-case and acts directly upon the heads of the trips m, to force them
longitudinally forward in the fuze-case so that their ends strike the retainers, or
the projections thereon, and forces them off the shoulder formed by the annulus 4,
so that no longer supported, they fall into the hammer chamber, thus entirely
freeing the hammer. During the flight of the shell the hammer remains in its
position against the rear wall of the chamber until the moment of impact of the
shell with its target when the hammer under momentum suddenly moves forward
and strikes one or more of the firing pins 1 and explodes the caps.
The hammer is thus released from the holding action of the retainers at the
moment of firing by the pressure of the firing charge acting against the heads of the
trips to move them longitudinally inwards against the retainers.
To aid in sustaining the hammer against the rear wall of its chamber a spring 9
is preferably employed, interposed in a central recess in the portion 11 of the fuze-
case and the hammer. This spring, while it may obviously be of any suitable form,
is shown as formed by a revolute ribbon.
The igniting charge is contained in the central recess of an elongation 24 of the
portion 11 of the fuze-case, being also partially contained and held in place by a
hollow plug 25 screwed into said elongation. This igniting charge provides one
form of delay in transmitting the flame from the cap to the bursting charge of the
shell; and it consists of a time train of the usual composition such as mealed
powder or rocket composition firmly compressed in the plug 25. The circumference
of the elongation is grooved to provide one or more circumferential pockets 16 for
a supplementary igniting charge which, through a number of ducts 17" is in com-
munication with the interior of the plug and the igniting charge therein by
ducts 17, the pocket or pockets for the supplementary charge being closed by
a thin fragile sleeve 18.
In front of this time train there is placed a small quantity of quick burning
powder 28 which also fills the ducts 17, and the supplementary charge may also be
formed of the same material filling the pockets 16 and the ducts 17".
With this arrangement of the igniting charge, the explosion of the cap e, through
the passage 3, and chamber 15, ignites the time train; the gases therefrom escape
rearward through the relief vent 26 into the hammer chamber, thus relieving the
chamber 15 thereof, and as soon as the flame reaches the quick burning charge 28,
it flashes either directly outward through the central perforation 27 of the plug, or
by the ducts 17 and 17ª to the supplementary charge in the pockets 16. Should
the gases accumulating in the hammer chamber exceed a certain pressure, such
pressure may act to force either one or both of the trips m rearward from the fuze-
case so that the gases may escape by the perforations 6 wholly therefrom, the said
trips acting in this instance as relief plugs or valves opening outward.

page_text: The head of the plug 25 (it might be the end of the elongation 24) is slightly
greater in diameter than the clongation 24; so as to overhang or project beyond
the latter and aid in preventing the bursting charge of the shell from packing
tightly around said elongation and in rear of the head of the plug. By this means
should the flame fail to escape by the central perforation 27, by reason of this
packing of the powder against it, due to the inertia of the powder at the time of
firing the shell, it will pass by the ducts 17 to the rear of the head to the loosely
packed powder of the shell and by the other ducts 17* to the supplementary charge
thus ensuring the igniting of the bursting charge.
In Fig. 4, (Sheet 3) the retainer a, is illustrated as formed of a metal annulus
with a number of spring fingers projecting therefrom adapted to be compressed
and lie against the wall of the hammer chamber with their ends against the
circumferential shoulder on the hammer. This retainer annulus is likewise pro-
vided with projections 5 extending into the path of the trips m, which in this
instance upon movement under the firing pressure bend said projections inwardly
from resting against the annulus 4, thus freeing the retainer, which under the
elasticity of its fingers against the wall of the hammer chamber, move it forward
so that the fingers are withdrawn from the shoulder of the hammer and occupy the
position shown in dotted lines. The retainer remains in this position during the
Hight of the shell, and at the moment of impact the hammer moves forward and
strikes one or more of the firing pins, explodes the caps and fires the charge
contained by the shell.
In Fig. 5, (Sheet 3) the hammer carries a rearwardly projecting pin 19 extending
into a hollow rear extension 20 of the fuze-case, which opens out rearwardly and is
guarded by the perforated plate 8, as in Fig. 1 (Sheet 3). The pin is formed with
a head and between this head and a shoulder in the case the retainer a, is located.
This retainer is of annular conical form with its forward portion divided into a
number of fingers (which form projections extending in the path of the trip)
resting upon the shoulder in the fuze-case and holding the hammer firmly to its seat
against the rear wall of its chamber.
In rear of this retainer is placed the trip m, mounted to slide in the hollow
extension 20. The trip is of plunger form recessed to straddle the pin 19, and the
retainer, and carries a packing disc on its head as before. At the moment of firing
the pressure acting against the head of the trip moves it inwardly against the
retainer, compresses its fingers and removes their ends from the shoulder against
which they rest, thus freeing the hammer which at the moment of impact moves
forward with the pin and retainer to strike one or more of the firing pins
as before.
The plug 25 is adapted to be readily removed from the fuze-case and replaced
by other similar plugs containing different burning or igniting charges suited to
the work to be done or the character of the target against which the shell is to be
used. For instance, such charges should be varied according to the time at which
it is desired the bursting of the shell should occur, varying also with the degree of
penetration desired before bursting aud the nature of the target whether it be
earthworks, a lightly armoured vessel, or an iron-clad.
The third part of the invention shown in Sheets IV to VI relates to an automatic
means for regulating the delay between the time of exploding the cap and explosion
of the shell bursting charge; and embraces broadly a burning or igniting charge
ignited on the explosion of the cap, and a controller or valve for automatically
delaying the ignition of or retarding the free burning of said charge.
In said drawings :―
Fig. 1. (Sheet 4) is a longitudinal sectional elevation of a fuze containing the
improvement in its preferred form.
Fig. 2, (Sheet 4) is a front view of the same, the front or auxiliary head being
removed showing the form of the interior walls of the recess holding the controller
or valve.
Fig. 3, (Sheet 4) is a face view of the controller or valve.

page_text: Fig. 4, (Sheet 4) is a sectional elevation of a portion of Fig. 1, (Sheet 4) with
the controller in its changed or forward position, and a modified form of its seat.
Figs. 5 and 6 (Sheet 4) are similar views showing changes in the arrangement of
the delay burning charge.
Figs. 7 and 8, (Sheet 5) are similar longitudinal sections of a modified form of
the controller in its two positions and a different arrangement of the burning
charge.
Fig. 9, (Sheet 6) is a similar sectional view of another modified structure.
Fig. 10, (Sheet 6) is a like section of still another form of the controller, and
Fig. 11, (Sheet 6) is a transverse vertical section of the same on the lineæ, *.
Fig. 12, (Sheet 5) is a sectional elevation of the improvement combined with a
different form and construction of fuze; and Fig. 13 (Sheet 6) is an end elevation
of the same.
The construction of the fuze corresponds in the main with that shown in
Sheet III.
The cap seat or seats are each in communication by a duct 3 with a central
perforation 26 in communication with the main burning or igniting charge provided
in Fig. 1 in a central longitudinal recess 15, in an auxiliary head f, screwed into
the end of the head e. This charge is in communication by one or more inclined
passages 17 with an exterior or circumferential chamber 16, containing a
supplemental burning charge that is confined by a fragile sleeve 18.
Interposed between the main burning charge and the cap or fulminate there is
provided a controller or valve 20 that is adapted to retard or delay the passage of
the flame from the cap to the burning charge, or to act as a means of checking the
free burning of said charge.
This controller is fitted to move longitudinally with respect to the fuze case
more or less freely in the central recess 26, the walls of which provide a number of
separated supports for the controller or valve with intermediate free passages, when
in its normal rear position as in Fig. 1, (Sheet 4) around it for the flame from the
cap to. the burning charge, but which when in its forward or moved position
tends to check or partially stifles the burning of the burning charge and thus
for the time being prevents the speedy communication of the flame with the bursting
charge in the shell.
This movement of the controller or valve takes place at the moment of impact
of the shell with the target, and at the time the hammer strikes and explodes the
fulminate, so that it is immediately placed in position to act as a means of delaying
the ultimate communication of the flame with the bursting charge.
The controller, preferably free of movement, presses with considerable force
against the forward face of the burning charge, this force being due to the violent
retardation in velocity of the mass of the controller and continuing so long as such
change in velocity exists. And should the shell remain in the target, or continue
its flight after striking the target, passing through it or beyond it according to the
nature of the target, the controller, due to the pressure exerted by the gases
generated in front of it, will return to its normal rearward position, permitting the
burning charge to burn freely, so that the flame therefrom immediately enters the
shell.and fires the bursting charge in the usual way.
In the preferred construction, there is provided a delay burning charge 4, which
may, or may not be, always exposed to the flame from the fulminate, which in the
moved position of the controller or valve takes the flame from the fulminate and
by reason of its different composition or harder packing, as may be preferred, burns
slowly with sufficient delay to prevent the immediate ignition of the main burning
charge, during, for instance, the penetration of the target by the shell, or even
during its further flight beyond the target.
In Fig. 1, (Sheet 4) the delay burning charge 4 is contained by a recess in the
face of the controller and thus moves with it. The walls of the recess are under-
cut so that the charge is properly held thereby, the face of the charge being in
the main exposed so that the flame may gradually burn from the exterior edge

page_text: thereof toward the centre. The rim of the recess is also cut away at several places,
see Fig. 3, (Sheet 4) so that the delay charge may fill these cut-away portions and
be exposed at the circumference of the controller in the path of the flame from the
fulminate so that its ignition is insured.
Instead of allowing the face of the delay burning charge to scat against the end
or contiguous surface of the auxiliary head f, which might be the case, there is
provided a seat 5, of felt or soft metal, such as lead, or in lieu of either of these, a
closely corrugated disc of copper may be used as seen in detail, Fig. 4 (Sheet 4).
The latter form presents instead of a flat or soft surface, a broken surface so
that the burning of the delay charge is allowed to spread gradually and is not
stifled too much.
In Fig. 5, (Sheet 4) the delay charge is arranged in perforations in the controller
passing from one face to the other, so that the controller must first move to its
forward position to place the delay charge in position to be ignited by the flamo
from the fulminate.
In Fig. 6, (Sheet 4) the burning charge, whether delay or flashing charge, is
arranged on the face of the auxiliary head, the controller in this case having
moved up to guard its surface and thereby retard the spread of the flame and
compelling its gradually burning inwardly toward the central chamber 15 as the
controller bears against its surface, but when it moves away from any cause as,
for instance, by the pressure of the gases in front of it, the flame will quickly
spread over the entire surface of the charge and immediately communicate with
the bursting charge in the shell.
During the flight of the shell and fuze, the retainers having been tripped from
the hammer by the firing pressure of the propelling charge, or by any other means
in other forms of fuzes, the parts will remain substantially in the same position as
that shown in Fig. 1, (Sheet 4) with the said one exception. As soon as the shell
strikes the target, the hammer moves forward against the firing pins by its
momentum and the controller or valve 20 is simultaneously moved forward so that
the delay charge is seated against the rear surface of the auxiliary head f, or of the
seat 5. In this position of the valve and delay charge, as in Fig. 4, (Sheet 4) the
flame from the cap, caused by the striking of the hammer, is for the time being
prevented from passing direct to the main burning charge and consequently fires
the delay charge only; or the flame from the fulminate ignites the edge of the
burning charge as in Fig. 6, (Sheet 4). This burns slowly inwardly, the gases
generated thereby passing upward around the valve and into the hammer chamber,
and if the pressure be great enough expels the trips outward and passes into the
atmosphere. The flame is thus delayed in passing to the main burning charge until
the delay charge, or exposed portion of the main charge, is nearly or wholly con-
sumed, when it immediately fires the burning charge in the central chamber 15 and
thence the supplemental charge in the exterior chamber 16, when the latter is used,
and finally enters the shell to fire the bursting charge.
After the first violent retardation of the shell upon striking the target and should
the shell continue its flight, the controller or valve will become seated again in its
rear position, so that the flame from the surface of the delay charge, or the exposed
portion of the main charge, may then immediately communicate with the main
burning charge and fire it without waiting for any further burning of the delay
charge to accomplish this, when the firing of the bursting charge takes place as
before, and this may occur during the further flight of the shell or after it has again
struck and its flight stopped entirely.
In Figs. 7 and 8, (Sheet 5) the head e, of the fuse case (the other parts of the
fuze being of any suitable construction, and being partially indicated in diagram)
is formed with a number of chambers or pockets 115, or one or more of which,
containing a burning or igniting charge, and closed in front by a removable plate 28
having a perforation 11 in line with one or more of the chambers. One or more of
these chambers is in communication by the duct 3 with the cap seat, and by a
duct 2 with an enlargement of the central recess 26, and thence past the controller

page_text: or valve therein through perforations 6 with the chamber or chambers 115 not in
direct communication with the cap seat.
The chamber in communication with the cap seat is preferably provided with the
delay burning charge 4, which may be separated from the main burning charge in
the same chamber by a perforated wad or diaphragm 7, screwed in place and
holding the delay charge, and the main charge held by the plate 28 or by a screw 8
which serves to secure the plate; said latter charge being in communication with
the central recess 26 through a perforation
shell or the exterior of the fuze-case by a perforation 10 as is also the other
and with the bursting charge of the
chamber 115.
The controller or valve in this form of the invention is in the form of a piston
held to its normal rearward position by a spring 27, which also performs the
function through the valve of holding the hammer c, to its rearward position, and
allowing the flame from the cap to pass by the duct 2 across the front of the valve,
across the recess 26 and through the perforations 6 and 9 into the chamber or
chambers 115 for firing the main burning charge. In the moved position of the
valve in Fig. 8, (Sheet 5) the recess is closed so that communication between the
ducts 3 and 2 with the chamber 115 by the perforations 6 or 9 is cut off and
the flame from the cap is confined to the delay burning charge 4 the gases resulting
therefrom passing by the duct 2 and perforations in the valve into the hammer
chamber. So long as the valve remains in this forward position, the flame is
confined to the delay charge and finally communicates through the perforation in
the wad or diaphragm 7 with the main burning charge and issues out of the
perforation 10 into the bursting charge of the shell. Should the shell remain in
the target or continue its flight after striking the target, the momentum of the
valve is overcome by the spring 27 and is forced backward to its normal position,
so that the flame from the ignited delay burning charge is free to pass in front of
the end of the valve and by the perforations 6.or 9 or both, into the main burning
charge or charges for the immediate ignition of the bursting charge either through
the perforation 10 or out through the front perforation 11.
In Fig. 9, (Sheet 6) the main burning charge is contained by an exterior
chamber 215 in the auxiliary head which screws into the head e, of the fuse case,
the charge being protected by a fragile sleeve 18, and in communication with the
central recess 26 by an inclined passage 12. The delay burning charge 4 is con-
tained by a chamber in the auxiliary head which is in communication by the duct 3
with the cap seat and is also open to the central recess 26. In this form the delay
charge will not completely fill its chamber so that a free passage is left in rear of
the charge from the duct 3 to the recess 26; and the front of the chamber is in
communication with the main burning charge chamber 215.
The controller or valve 20 is similar to that described with respect to Figs. 7
and 8, (Sheet 5) except that it is provided with a sub-calibre stem, which, in its
normal rearward position, forms sufficient space for the passage of the flame from
the cap seat or delay charge across the central recess to ignite main burning charge
through the inclined passage 12 and thence the bursting charge in the shell as
before. In the changed position of the valve, it closes the entrance to the central
recess or shuts off the entrance to the main burning charge so that the flame from
the cap is confined to the delay charge, the gases generated from the burning of
the latter are free to pass into the hammer chamber through the perforated head
of the valve which then registers with the central space that is in communication
with the chamber containing said delay charge.
In Figs. 10 and 11, (Sheet 6) the main burning charge is confined in a central
chamber 315, formed by a rearwardly extending nipple, the end of which has a
number of radial openings which also contain some of the burning charge. There
is provided the supplemental burning charge 16 protected by the fragile sleeve 18,
but having no communication with the main burning charge. With this supple- 5
mental charge there is one or more communicating chambers containing the delay
charge 4 that is open to the duct 3 with the cap-seat, and by a duct 2 with the

page_text: central recess around the nipple containing the main burning charge. The main
burning charge through the radial openings in the nipple is protected by a fragile
sleeve 13, surrounding the nipple and adapted to slide forward thereon to uncover
the openings. The end of the nipple is embraced by the controller or valve 20,
which is in the form of a thimble held extended and in its rearward normal position
against the hammer c, by the spring 27 and capable of sliding over the nipple at
the moment of impact of the shell with the target to move the sleeve 13 forward to
uncover the openings in the nipple and then to cover said openings to prevent the
flame from igniting the main burning charge. As soon as the spring 27 can act to
overcome the momentum of the valve, it moves the latter rearward and uncovers
the radial openings through the nipple and permits the flame from the delay charge
to ignite the main burning charge and thence the bursting charge in the
usual way.
In Figs. 12 and 13, (Sheet 5) the fulminate is carried by a longitudinally movable
block 120, which acts as the controller or valv. The forward end of the block
carries the delay charge in a manner similar to the valve of Fig. 1, (Sheet 4) an
the duct 3 from the cap seat opens outward at the forward end of the head, which
end is normally seated against the rearward end of the screw cap 35, or against a
felt or soft metal scat 5. The screw cap is formed with two diametrical channels 36.
which contain the main burning charge open to the flame from the delay charge
through rear openings 37. At the moment the shell is propelled in the gun, the
hammer c moves rearward over the firing pin 1, so as to uncover or project its end
forward beyond the hammer in a manner now well known. The block 120, carrying
the fulminate, likewise moves rearward up to the shoulder of the fuze case, and at
the moment of impact the hammer and firing pin and the block are simultaneously
thrown forward until the delay charge of the block is seated against the seat 5, while
the firing pin is projected into the fulminate cavity and explodes the fulminate.
The delay charge is thereupon immediately ignited from the centre and burns out-
wardly while the gases generated thereby escape rearward through the channel in
the block and into the hammer chamber. Should the shell remain in the target, or
continue its flight, the gases accumulating between the seat 5 and the delay charge
will move the block 120 rearward away from the seat so that the flame quickly
spreads and thence fires the main charge, and through the central perforation in the
screw cap, fires the bursting charge of the shell.
In each of the several embodiments, the controller or valve 20 or the block 120
moves at the time of impact of the shell with the target to guard or control the
freedom with which the burning charge shall burn, or to cut off a portion of the
charge, and after the first sudden retardation of the shell, either by the pressure of
the gases generated by the burning charge or by a spring, the controller or the block
is caused to resume its other position allowing the flame to spread to all parts of the
charge immediately or as quickly as the nature of the charge and the manner it is
packed will permit. By this means the flame from the fulminate is prevented from
immediately igniting the bursting charge at the moment of impact with the target,
but a short delay occurs sufficient to allow the shell to penetrate the target, bursting
while in the target or after passing through it according as the bursting charge may
have been prepared for the purpose.
It is obvious that any means of preventing the action of the controller or valve
may be employed. Thus in Fig. 1, (Sheet 4) there is provided a screw pin i, which,
when moved inwardly serves as a stop. preventing the movement of the controller.
In the form shown in Figs. 7, 8, 9 and 10, the controller may be removed entirely,
and the flame from the fulminate ignite both the delay and the main burning
charges.
While in the arrangement of the controller or valve as shown and described said
valve moves at the time of impact into its controlling position, it is to be distinctly
understood that it may be so arranged as to be normally in the controlling position
and adapted to be moved automatically after impact, as, for instance, by the pressure
of the accumulating gases behind it, forcing it from its controlling position, so as to
B

page_text: open communication between the flame and the burning charge. In fact, so many
different arrangements of valves, for delaying the ignition of the burning charge,
may obviously be made, that I do not intend to limit the invention to the particular
forms shown and described.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed, I declare that what I
claim is :-
1. In a fuze, the combination with a hammer and a seat for a cap, of a stop for
the hammer, normally preventing the movement thereof and an independent trip for
releasing said stop and allowing the hammer to operate, substantially as described.
2. In a fuze, the combination with the hammer and the cap, of an independent
retainer, holding the hammer against movement, and a trip exposed to the firing
pressure, whereby it is moved at the time of firing to meet a projection on the
retainer, to disengage the latter to free the hammer, substantially as described.
3. In a fuze, the combination with the fulminate and means for exploding it, and
a burning charge ignited from the fulminate, of a controller or valve interposed
between the fulminate and the burning charge for delaying the ignition of or
retarding the free burning of said charge, substantially as described.
Dated this 29th day of February 1891.
H. D. FITZPATRICK,
70, Wellington Street, Glasgow, Agent.