Improvements in Percussion Fuses.
Year: 1891

page_text: Date of Application, 4th June, 1891
Complete Specification Left, 1st Mar., 1592-Accepted, 16th Apr., 1892.
PROVISIONAL SPECIFICATION.
Improvements in Percussion Fuses.
1. HAROLD THOMAS ASHTON, of The Royal Laboratory, Woolwich in the
County of Kent, Engineer, do hereby declare the nature of this invention to be as
follows:-
-
My invention relates to percussion fuses of the kind in which a pellet, on the
projectile being arrested or retarded, moves forwards against a needle which fires
the detonator.
The object which I have in view is to prevent accidental or premature firing, for
which purpose I adopt the following construction. I fit in the centre of the front
part of the fuse a stop screw having a square shank which prevents it from
turning, this shank projecting backwards and bearing against the front of the pellet.
and preventing it from advancing.
On the front part of the screw is fitted a nut on which, as on a bobbin is wound
a ribbon of lead or other heavy flexible material or it might be a chain, the one
As the
end of which is fixed to the body of the fuse and the other end to the nut.
projectile to which the fuse is applied revolves during its flight, the ribbon or
chain, owing to centrifugal force, tends to unwind itself and causes the nut on
which it is wound to revolve, thereby screwing forwards the stop screw and so
leaving the pellet free to advance and fire the detonator when the projectile
becomes stopped or retarded. By this arrangement the pellet is always held back
until the revolution of the projectile during flight sets it free, and consequently,
there is no risk of firing during the handling of the fuse or projectile.
The revolution of the nut resulting from centrifugal force, instead of being
applied to withdraw a stop screw and so release the pellet, as above described, may
screw a detonating needle out of a hole in which it was shrouded and make it
approach towards the pellet, which is retained in a back position by a spring or
otherwise until, on the projectile being retarded or stopped, it advances to the
needle which fires the detonator.
In a modified arrangement of the fuse I utilise centrifugal force for preventing
premature detonation during the flight of the projectile in the following manner.
I bore the cylindrical cavity of the fuse in which the pellet is fitted to slide, not
axial with the fuse, but slightly inclined to its axis, and I so proportion the pellet
that, when it is in its rear position its centre of gravity is a little to one side of
the fuse axis. As the projectile revolves during flight, centrifugal force causes
the pellet to retain its rear position, and prevents it from advancing to fire the
detonator until the projectile becomes arrested or retarded.
Dated this 4th day of June 1891.
ABEL & IMKAI,
Agents for the Applicant.
COMPLETE SPECIFICATION.
Improvements in Percussion Fuses.
1, HAROLD THOMAS ASHTON, of The Royal Laboratory, Woolwich, in the
County of Kent, 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:-
My invention relates to percussion fuses of the kind in which a pellet, on the
projectile being arrested or retarded, moves forwards and strikes a needle or moves

page_text: forwards with it a needle which fires the detonator. The object which I have in
view is to prevent accidental or premature firing, for which purpose I adopt
constructions of fuses such as I shall describe referring to the accompanying
drawing.
b
Fig. 1 is a longitudinal section and Fig. 2 is a sectional plan on X X of one
form of fuse according to my invention. P is the pellet which is fitted to slide
freely within the body of the fuse F but is prevented from moving forwards
towards the needles N by a pin having its upper portion a screw threaded and its
lower portion square and fitting in a square hole to prevent it from turning. On
the upper part a is fitted a dovetailed nut c to which is attached one end of a
ribbon of lead or of lead alloyed with tin, this ribbon being coiled several times
round the nut and having its other end attached to the body of the fuse. When
the projectile rotates on being fired from a rifled gun, the centrifugal force causes
the ribbon to uncoil itself turning the nut c; the pin abis thus screwed forward
leaving the pellet P free to advance against the needles N when the projectile is
stopped or retarded. In order to avoid danger during transport of the fuses or of
the shells to which they are applied the nut c is kept from turning and the cap d
from becoming unscrewed by the insertion of a split pin e indicated by dotted lines,
which is not removed until the projectile is ready to be placed in the gun.
Fig. 3 is a longitudinal section, Fig. 4 is a sectional plan on X X and Fig. 5 is
a sectional plan on Y Y looking from below, of a modified construction. In this
case the pellet P is prevented from advancing against the needle N by two
pillars interposed between the pellet and a piece which is coiled with the
metal ribbon. The under face of the piece has two opposite notches large
enough to admit the pillars of which the one is a little longer than the
other and consequently the segment against which the longer pillar g bears is
less prominent than the other segment against which the shorter pillar bears.
When the projectile rotates, the piece is turned in the direction of the arrow
until the more prominent segment is stopped against the end of the longer
pillar in which position the notches between and coincide with the pillars.
When the projectile stopped or retarded, the pillars yg being free to enter
the notches, the pellet P advances against the needle N.
ول
I
as
Instead of the metal ribbon shewn in the figures, a chain might obviously be used
to act in a similar manner by uncoiling itself in obedience to the centrifugal force.
This force may however be also applied in another manner to release the pellet
I shall now describe referring to Fig. 6 which is a longitudinal section, Fig. 7 which
is a sectional plan on Z Z and Fig. 8 which is a side view of the stop S. In this
case the pellet P is held by a nut on a bolt B which has at its front the needle N.
The head of the bolt B is under the round stop S which has two ribs projecting
up from it. Two studs kk' are fitted in transverse holes and are urged towards the
axis of the fuse by light springs behind them, thus forming stops against the ribs r
to prevent the stop S from turning in the direction of the arrow. A set screw t
bearing against prevents it from turning in the opposite direction.
2"
As in the constructions previously described the metal ribbon or chain / is coiled
around the stop S. When the projectile rotates the centrifugal force causes the
studs to move outwards releasing the ribs and the ribbon or chain l
uncoiling causes the stop S to revolve until the rib is stopped by the set screw t the
two ribs being in this position coincident with notches in the body of the fuse
above them.
7°
When the projectile is stopped or retarded, the ribs being free to enter the
notches above them, the pellet and needle advance effecting the firing.
Having now particularly described and ascertained the nature of this inven-
tion and in what manner the same is to be performed, I declare that what I
claim is
1. A percussion fuse wherein the firing pellet is obstructed by a pin or other stop
which is moved into a position to release the vellet by the uncoiling of a coiled

page_text: metal ribbon or chain resulting from centrifugal force when the projectile rotates,
substantially as described.
2. The construction of fuse substantially as described with reference to Figs. 1
and 2.
3. The construction of fuse substantially as described with reference to Figs. 3, 4
and 5.
4. The construction of fuse substantially as described with reference to Figs. 6, 7
and 8.
Dated this 1st day of March 1892
ABEL & IMRAY,
Agents for the Applicant.