IMPROVEMENTS IN ENVELOPES FOR THE PROJECTILES OF RIFLED SMALL ARMS
Year: 1883

page_text: "
LETTERS PATENT to Sydney Pitt of Sutton in the County of Surrey for an
Invention of "IMPROVEMENTS IN ENVELOPES FOR THE PROJECTILES OF RIFLED
SMALL ARMS communicated to him from abroad by Lieut: Colonel George
Vincent Fosbery V.C. of Upton Manor Bitton near Bristol now residing at
Liegé Belgium and Henri Pieper of Liege aforesaid Gun Manufacturer.
PROVISIONAL SPECIFICATION left by the said Sydney Pitt at the Office
of the Commissioners of Patents on the 13th March 1883.
"
SYDNEY PITT of Sutton in the County of Surrey. "IMPROVEMENTS IN
ENVELOPES FOR THE PROJECTILES OF RIFLED SMALL ARMS [communicated to
him from abroad by Lieut: Colonel George Vincent Fosbery V.C. of Upton Manor
Bitton near Bristol now residing at Liegé Belgium and Henri Pieper of Liegó
aforesaid Gun Manufacturer.]
This Invention has for its object improvements in envelopes for the projectiles of
rifled small arms.
For this purpose an envelope of sheet metal (preferably brass) is substituted for
the paper envelope now in use-it is formed of the same thickness as the paper one
hitherto used.
To form this sheet metal envelope a cross shaped piece or piece of other such
like form is cut from a sheet of thin metal.
Each such sheet metal blank is formed in a die into a cylinder closed at one
end and of such a size that a bullet may enter it and that it may enter the
cartridge.
This envelope is made slightly curved outwards at its upper edge-The portion
of it which is to be left projecting beyond the cartridge is formed with saw tooth
cannelures the teeth directed towards the point of the projectile.
These teeth may have a depth equal to that of the grooving of the rifle.
Or
the sheet metal may be pierced with holes and lined or covered in parts with other
substances
These cannelured may be filled with a lubricant preferably a mixture of vaseline
and paraffine.
The lower part of the envelope which enters the cartridge case may be cannelures
vertically to give better adherence to the bullet.
The bottom of the envelope may be flat convex or concave. By doubling the
metal on itself, round the lower edge a gas check may be formed.

page_text: by the said Sydney Pitt in the Great Seal Patent Office on the
13th September 1883.
"
SYDNEY PITT of Sutton in the County of Surrey "IMPROVEMENTS IN
ENVELOPES FOR THE PROJECTILES OF RIFLED SMALL ARMS A communication to
me from abroad by Lieut. Colonel George Vincent Fosbery V.C. of Upton Manor
Bitton near Bristol now residing at Liège Belgium and Henri Pieper of Liège
aforesaid Gun Manufacturer
This Invention has for its object improvements in envelopes for the projectiles
of rifled small arms.
For this purpose an envelope of sheet metal (preferably brass) is substituted. for
the paper envelope now in use-it is formed of the same thickness as the paper one
hitherto used.
To form this sheet metal envelope a cross shaped piece or piece of other such
like form is cut from a sheet of thin metal.
Each such sheet metal blank is formed in a die into a cylinder closed at one
end and of such a size that a bullet may enter it and that it may enter the
cartridge.
This envelope is made slightly curved outwards at its upper edge. The portion
of it which is to be left projecting beyond the cartridge is formed with saw tooth
cannelures the teeth directed towards the point of the projectile.
These teeth may have a depth equal to that of the grooving of the rifle. Or
the sheet metal may be pierced with holes and lined or covered in parts with other
substances.
The cannelures may be filled with a lubricant preferably a mixture of vaseline
and paraffin.
The lower part of the envelope which enters the cartridge case may be cannelured
vertically to give better adherence to the bullet.
The bottom of the envelope may be flat convex or concave. By doubling the
metal on itself round the lower edge a gas check may be formed.
Figure 1 of the Drawings hereunto annexed shows a longitudinal section of a
thin sheet metal cylindrical envelope for a projectile-the envelope is closed at its
rear end and has ratchet like teeth formed around its front end. Figure 2 shows
a longitudinal section of an envelope of this kind fitted over the rear end of a
projectile. Figure 3 shews a longitudinal section of the envelope and projectile
secured at the forward end of an ordinary metallic cartridge case."
The envelope may be made from a cross shape blank of thin sheet metal such
as shewn at Figure 4. The cross shape blank may be formed in a die into a
cylinder closed at one end as shewn in the longitudinal section Figure 5 and end
view Figure 6. The ratchet like teeth may subsequently be formed around its
front end. This may be effected by placing the thin sheet metal cylinder on to a
plunger having ratchet like teeth formed around it where the teeth are to be
formed and by causing the plunger to carry the cylinder forward between toothed
arcs or wheels ranged radially around the central axis of the plunger so that the
sides of the thin sheet metal cylinder may be nipped between the teeth on the
arcs or wheels and the teeth on the plunger. Or the teeth on the mandril might
be formed as a screw thread winding around its circumference and the sheet metal
of the cylinder be pressed into such screw thread by surfaces caused to turn or roll
around the screw thread so as to press the sheet metal into the screw teeth.
In place also of the teeth being formed after the sheet metal blank has been

page_text: shaped into a cylinder they might be formed at the ends of each arm of the cross
shaped blank before binding it up into a cylinder. Any suitable mechanism for
crimping or moulding teeth upon the ends of the several arms of the blank might
be employed. One way in which the teeth may be moulded upon the ends of the
arms is to place each blank upon a cross shape die which has teeth moulded upon
it and then to press the metal of the blank into the teeth by means of blades
acting in succession one after the other to press the metal into succeeding teeth.
In all cases it is desirable that unless a very small number of teeth are to be formed
at the end of each arm of the blank the teeth should not be all formed at once but
be formed in succession one after the other otherwise the sheet metal is subjected
to too great a strain and becomes torn.
Although I prefer that the ends of the arms should have a number of ratchet
teeth moulded upon them as above described it is not essential that they should be
so moulded with teeth upon them the extreme ends of each arm might simply be
made to bend outwards as shown at Figure 7.
In all cases it is preferred that the extreme end of the cylindrical case should be
made to bend outwards even when the case has ratchet teeth formed around its
sides as shewn at Figures 1. 2. and 3. The front edge of the cylinder will then
act as a scraper along the interior of the barrel that the projectile is fired from and
clean away all fouling from it. It will also so soon as the projectile leaves the
barrel meet with resistance from the air and the casing will thereby be made to
open out and drop off from the projectile.
At Figure 8 I have shewn a sheet metal envelope similar to that shewn at
Figure 1 but with longitudinal grooves in addition formed along it. At Figure 9
I have shewn a sheet metal envelope similar to that shewn at Figure 7' but with
in addition perforations formed through its sides. The holes may be punched so
as to leave a rough burred edge around each hole on the outer side of the envelope.
If desired the base of the sheet metal envelope may be formed into a gas check
by doubling the metal at the base of the envelope in the manner shown at
Figure 10.
Having thus described the nature of the invention and the manner of performing
the same I would have it understood that what is claimed is :-
First The construction of envelopes for projectiles from thin sheet metal as
hereinbefore described.
Second The construction of envelopes for projectiles of cylinders formed from
thin sheet metal and having teeth formed around their sides or having their
forward ends bent outwards as herein before described.
In witness whereof I the said Sydney Pitt have hereunto set my hand and
seal this eleventh day of September in the year of our Lord One thousand eight
hundred and eighty three.
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