Improvements in Percussion Fuzes for Explosive Projectiles or Shells.
Year: 1897

page_text: Date of Application, 11th Aug., 1897
Complete Specification Left, 11th May, 1898-Accepted, 11th Nov., 1898
PROVISIONAL SPECIFICATION.
Improvements in Percussion Fuzes for Explosive Projectiles or
Shells.
We, FREDERICK MARTEN HALE, General Manager of The New Explosives
Company, Limited, of 75, Queen Victoria Street, in the City of London, JAMES
DEAS, Engineer, of 4, Vicarage Park, Plumstead, in the County of Kent, and
JOHN BRODIE REAVIL, Engineer, of 2, Limes Villas, Humber Road West, Black-
heath, in the County of Kent, do hereby declare the nature of this invention
to be as follows;-
This invention relates to percussion fuzes of the kind in which a firing point or
needle and a percusion pellet, having a detonator, are so arranged that the said
detonator normally lies out of alignment with the said firing point or needle and
can only come into alignment therewith by the rotation of the shell during its
flight from the gun.
According to our invention we locate within a cavity with which the body of
the fuze is formed, a rotary pellet carrying a detonator, the said pellet being
provided with pivots or axles that lie co-axial with the longitudinal axis of the
fuze. The shape of the said pellet is such that the centre of gravity thereof is
excentric to the axis of the said pivots or axles. The pellet is furnished with one
or more laterally disposed bolts, the heads of which are, by means of springs kept
in engagement with recesses formed for their reception in the body of the fuze,
whereby the pellet is held locked to the fuze body and rendered incapable of per-
forming any independent movement. In this position of the pellet, the detonator
it carries is out of alignment with the firing needle. The tails of the said bolts
are weighted and occupy such a position relatively to the longitudinal axis of
the fuze that during the flight and spin of the shell to which the fuze is applied,
the heads of the said bolts are caused by centrifugal force acting on the said
weighted tails, to be withdrawn from their recesses in the fuze body and thereby
release the pellet from its locked position. The rotation of the pellet then becomes
independent of the rotation of the fuze; that is to say, by reason of the excentric
position of the centre of gravity of the said pellet, the speed of its rotation is
reduced while the speed of rotation of the fuze body remains unchanged, with
the result that the position of the detonator with respect to the firing needle is
altered and the detonator quickly comes into alignment with the firing needle.
Immediately this alignment occurs, a spring bolt carried by the pellet is caused
to be thrust into a longitudinal slot in the fuze-body by a spring whereby the
pellet is locked to the fuze body in its new angular position. The aforesaid
longitudinal slot in the fuze body renders the pellet free to move longitudinally
forward on impact of the shell and consequently when such impact takes place
the said pellet will, by its own momentum, fly forward and cause its detonator
to strike the firing needle; and the resulting "flash" explodes the shell as is
well understood.
In order to permit of this longitudinal forward movement of the pellet, the

page_text: pivots or axles thereof are made somewhat long so that they can slide longi-
tudinally in their bearings without any liability of the pellet becoming dis-
engaged from the said bearings. The forward end of the fuze body is provided
with a screw plug for closing the aforesaid cavity in the fuze body and this plug
is furnished with a projection which is so arranged that it will lie contiguous
to the end of the aforesaid pellet and restrain the latter from longitudinal move-
ment until it has assumed its position of alignment with the firing needle. This
projection also reduces the transverse stress that would otherwise come upon the
aforesaid lateral bolts carried by the pellet and enables them to readily shift when
subjected to the action of centrifugal force during the flight of the shell.
If desired the front pivot or axle of the pellet may be provided with a spring,
which will offer sufficient resistance to the longitudinal movement of the pellet
to ensure that it shall not shift longitudinally forward towards the firing needle
before impact of the shell occurs.
It will be obvious that the construction of our fuze and the arrangement of its
parts can be varied considerably without departing from the nature of our inven-
tion, the chief object of which is to so construct a fuze that an excentrically dis-
posed rotary detonator pellet will be normally held out of alignment with a firing
needle until released by centrifugal force acting on locking bolts during the flight
of the shell; the said pellet, owing to its excentricity, then changing its position
angularly and thus bringing its detonator into alignment with the firing needle
so that on impact the detonator will strike said needle and explode the shell.
Dated this 11th day of August 1897.
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, W.C.,
Agents for the Applicants.
Improvements in Pereussion Fuzes for Explosive Projectiles or
Shells.
We, FREDERICK MARTEN HALE, General Manager of The New Explosives
Company, Limited, of 75, Queen Victoria Street, in the City of London, JAMES
DEAS, Engineer, of 4, Vicarage Park, Plumstead, in the County of Kent, and
JOHN BRODIE REAVIL, Engineer, of 2, Limes Villas, Humber Road West, Black-
heath, in the County of Kent, 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 of the kind in which a firing point or
needle and a percussion pellet having a detonator, are so arranged that the said
detonator at first lies out of alignment with the said firing point or needle and
only comes into alignment therewith by the rotation of the shell during its flight
from the gun.
According to our invention we so construct the fuze that'a rotative detonator
pellet, which is excentrically disposed within the fuze body, will be normally
retained out of alignment with the firing needle until released by centrifugal
force acting on locking bolts during the Hight of the shell, the said pellet, by
reason of its excentricity, then changing its position angularly until it brings
its detonator in alignment with the firing needle. In this position the pellet is
restrained from further angular movement but is free to shift longitudinally on
impact and cause its detonator to strike the needle and explode the shell.

page_text: In order that our said invention may be clearly understood and readily carried
into effect we will proceed to describe the same more fully with reference to the
accompanying drawings, in which we have illustrated our 'improved fuze in a
form to be applied to the base of a shell.
Figure 1 is a central longitudinal section with the parts in an inactive position,
that is to say in the position they occupy before discharge of the shell from the
gun.
Figure 2 is a similar section taken at right angles to Figure 1.
Figures 3 and 4 are sectional views corresponding to Figures 1 and 2, and
illustrating the parts in the position they occupy after discharge of the shell
from the gun.
Figure 5 is a sectional view similar to Figure 3 but showing the parts in the
position they occupy immediately after impact.
Figure 6 is a transverse section on the line 1, 1 of Figure 1.
Figure 7 is a plan of a screw plug forming part of the fuze, as hereinafter
described.
In all these figures like letters of reference indicate similar parts.
A is the body of the fuze within a cavity A¹ of which is located the pellet B
having pivots or axles b b co-axial with the longitudinal axis of the fuze. The
shape of the said pellet is such that the centre of gravity thereof is excentric to
the axis of the said pivots or axles. It is furnished with one or more laterally
disposed bolts C the heads c of which are, by means of springs c¹, kept in engage-
ment with recesses a formed for their reception in the body A. of the fuze. The
pellet is by means of such bolts held locked to the fuze body and rendered in-
capable of performing any independent movement. In this position of the
pellet, the detonator B¹ which it carries, is out of alignment with the firing
needle D. The tails 2 of the said bolts are weighted and occupy such a position
relatively to the longitudinal axle of the fuze that during the flight and spin of
the shell to which the fuze is applied, the heads c of the said bolts are caused
by centrifugal force acting on the said weighted tails to be withdrawn from
their recesses in the fuze body and thereby release the pellet from its locked
position. The rotation of the pellet about its pivot pins b b then becomes inde-
pendent of the rotation of the fuze and by reason of the excentric position of the
centre of gravity of the said pellet, the speed of its rotation is diminished while
the speed of rotation of the fuze body remains unchanged. The position of the
detonator B with respect to the firing needle D is thereby altered and continues
to alter until the said detonator comes into alignment with the firing needle.
Immediately this alignment occurs, a bolt E carried by the pellet is caused to
be thrust into a longitudinal slot A2 in the fuze body by a spring e whereby the
pellet is locked to the fuze body in its new angular position (see Figures 3 and 4).
But. the aforesaid longitudinal slot A2 leaves the pellet free to move forward on
impact of the shell and consequently when such impact takes place the said pellet
will, by its own momentum, Hy forward and cause its detonator B¹ to strike the
firing needle D. The resulting "flash" explodes the shell as is well understood.
In order to permit of this longitudinal forward movement of the pellet, the
pivots thereof and their bearings are made so long that the pivots can slide
longitudinally therein without any liability of the pellet to become disengaged
from the said bearings.
The forward end of the fuze body is provided with a screw plug D¹ for closing
the aforesaid cavity A¹ and this plug is furnished with a projection D2 which is
so arranged that it will lie contiguous to the end of the aforesaid pellet (see
Figure 1) and restrain the latter from longitudinal movement until the detonator
has assumed its position of alignment with the firing needle. This projection D²
also reduces the transverse stress that would otherwise come upon the aforesaid
lateral bolts C C carried by the pellet and enables them to readily shift when
subjected to the action of centrifugal force during the flight of the shell.
The said plug D' has a series of flash holes & contiguous to the firing needle D

page_text: such holes opening into a cavity d¹ containing an explosive mixture which is
fired by the flash on impact of the shell. In order to ensure that the flash shall
be effectually projected through the said holes d we prefer to provide a cavity ba
containing an explosive mixture immediately at the rear of the detonator B₁, so
that on explosion of the detonator this explosive mixture will likewise be fired
and give rise to a flame that will extend completely through the flash holes. It
will be obvious that the position of the firing needle and the detonator may be
reversed, that is to say the firing needle may be arranged on the pellet and the
detonator on the plug D¹. Likewise the bolts C and E may be arranged in the
fuze body instead of in the pellet.
If desired the front pivot or axle of the pellet may be provided with a spring,
which will offer sufficient resistance to the longitudinal movement of the pellet to
prevent its shifting longitudinally forward towards the firing needle before im-
pact of the shell occurs.
Having now particularly described and ascertained the nature of our said
invention and in what manner the same is to be performed, we declare that what
we claim is:-
1. A percussion fuze provided with an excentrically arranged rotative pellet
which is released by centrifugal force during the flight of the shell and then
operates substantially as described.
2. The combination with the rotative excentric pellet of a screw plug 11
arranged substantially as described and provided with a projection D2 for the
purpose specified.
3. The combination with the rotative excentric pellet of bolts C and E arranged
substantially as described and for the purposes specified.
4. A percussion fuze having its parts constructed, arranged and combined sub-
stantially as described with reference to the accompanying drawings to operate
as and for the purposes specified.
Dated this 11th day of Mar 1808
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, W.C.,
Agents for the Applicants.