IMPROVEMENTS IN ORDNANCE AND PROJECTILES THEREFOR
Year: 1870

page_text: PROVISIONAL SPECIFICATION left by Henry Huthnance at the Office.
of the Commissioners of Patents, with his Petition, on the 13th
October 1870..
i
I, HENRY HUTHNANCE, of Southampton, in the County of South-
ampton, Engineer, do hereby declare the nature of the said Invention'
for "IMPROVEMENTS IN ORDNANCE AND PROJECTILES THEREFOR," to be as
follows:-
This Invention relates, firstly, to cannon and mortars, and consists in
the application thereto of a longitudinal bar secured centrally inside the
bore of the cannon or mortar so as to coincide exactly with the axial
line thereof; this bar is of a square or other flat sided section, or its,
section may be of an oval form, and it is twisted axially so as to make
the edges or corners form a spiral throughout its entire length with the
exception of a short portion at or near the breech end of the gun or
mortar which may be left cylindrical, and which should be provided with a
screwed stem for screwing it into the metal, forming the breech end of
the gun or mortar. The object of this bar is to produce the rotation of
the projectile without having recourse to the ordinary rifle grooves made
:

page_text: in the sides of the bore, which tend to weaken the piece, moreover the
fact of the spiral being put into a central rod in the axial centre of the
bore in lieu of in the periphery of the bore, or at a distance from the
centre, admits of a quicker turn or spiral being employed. Various
means may be employed for securing the twisted rod into the breech of
the piece of ordnance, but the screwing of it therein will be found to
answer well in practice, the escape of the gases being prevented by the
interposition of a copper washer between a shoulder on the rod and the
interior of the breech end of the piece.
The second part of this Invention relates to the projectiles for these
improved ordnance, and consists in forming them with a central aperture
corresponding with and fitting easily the twisted rod, so that when fired
the traverse of the projectile along the twisted rod will cause the desired
spin or rotatory motion to be imparted to the same. The projectiles are
of an oblong form, and whether solid or hollow (but more particularly in
the former case) are provided at the middle portion with outer packing
rings of wood or other suitable material made in halves or segments so
disposed as to break joint with each other. Other rings which may be
solid or undivided are situate at the front and rear ends of the projectiles,
and have their inner faces bevilled to correspond to similar bevels on the
outer faces of the inner segments. The front ring is fixed but the rear
one is loose and is pressed forward by the explosion, so as to cause the
inner segments by the action of the bevels or inclines to be wedged
outwards and fit closely against the smooth bore of the gun or mortar,
thus preventing windage. On escaping from the muzzle these rings and
segments become of themselves detached from the projectile, leaving the
body part thereof alone to pursue its flight. By this means a large area
is obtained for the gases to exert their force against with a comparatively
small projectile. The same system of external packing rings and
segments is also applicable to ordinary elongated projectiles for smooth
bore guns.
The twisted bar herein-before referred to may also be
obviously applied to the firing of rockets for military purposes.