IMPROVEMENTS IN GUN POWDER M. PROVISIONAL SPFIC
Year: 1883

page_text: LETTERS PATENT to Thorsten Nordenfelt of 53 Parliament Street in the City
of Westminster for an Invention of "IMPROVEMENTS IN GUN POWDER
M.
PROVISIONAL SPECIFICATION left by the said Thorsten Nordenfelt at the
Office of the Commissioners of Patents on the 19th October 1883.
THORSTEN NORDENFELT of 53 Parliament Street in the City of Westminster
$6 IMPROVEMENTS IN GUN POWDER
This Invention has for its object improvements in gun powder.
At the present time it is common to mould powder intended for heavy ordnance
into hexagonal or prismatic blocks having flat ends.
Now I form such blocks with convex ends in order that the surfaces may ignite
with greater certainty at the first moment.
It is also usual to form these bexagonal or prismatic powder blocks with a hole
formed through the axis of the block.
The object for which this hole is provided is :-
First, to offer at the moment of ignition a larger surface to the flame.
Second, to regulate the surface of combustion; as the outer side decreases by
being burnt away the inner side increases by the enlargement of the hole..
But a powder grain with a hole through it is liable to be broken by the pressure
of the gas within it immediately after ignition, in which case the surface of com-
bustion is largely and suddenly increased and there is risk of an excessive pressure
being generated such as might strain or burst the gun..
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To avoid this risk I substitute for the perforation, indentations on the two
opposite surfaces of the grain, such that the first igniting surface is. as large or
nearly as large as when the grain is perforated and the curvature of the surfaces
favorable to regular ignition. The grains so formed are much less liable to be
broken on ignition than are grains which are perforated in the usual way.
the grain burns away the indentations presently meet and after that moment the
grain becomes a perforated grain and operates in a similar manner.
If the grain
should break at this stage in the latter stages of combustion no harm will result as
the projectile has then already proceeded a considerable distance along the bore
and the pre-sure behind it has fallen considerably.
The means employed for effecting the object of the invention are as follows:-
Moulds are prepared corresponding in form to the blocks of powder described
above and in these moulds Gunpowder is consolidated-by bydraulic or other
pressure.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said Thorsten Nordenfelt in the Patent Office on the 18th April
1884.
THORSTEN NORDENFELT of 53 Parliament Street in the City of Westminster
"IMPROVEMENTS IN GUN-POWDER
"
This invention has for its object improvements in gunpowder.
At the present time it is common to mould powder intended for heavy ordnance
into hexagonal or prismatic blocks having flat ends.
Now I form such blocks with convex ends in order that the surfaces may ignite
with greater certainty at the first moment.
It is also usual to form these hexagonal or prismatic powder blocks with a hole
formed through the axis of the block.
The object for which this hole is provided is :-
First To offer at the moment of ignition a larger surface to the flame.
Second-To regulate the surface of combustion: as the outer side decreases 1
by being burnt away the inner side increases by the enlargement of
the hole.
But a powder grain with a hole through it is liable to be broken by the pressure
of the gas within it immediately after ignition-in which case the surface of
combustion is largely and suddenly increased and there is risk of an excessive
pressure being generated such as might strain or burst the gun.
To avoid this risk I substitute for the perforation indentations on the two
opposite surfaces of the grain such that the first igniting surface is as large or
nearly as large as when the grain is perforated and the curvature of the surfaces
favorable to regular ignition. The grains so formed are much less liable to be
broken on ignition than are grains which are perforated in the usual way. As the
grain burns away the indentations presently meet and after that moment the grain
becomes a perforated grain and operates in a similar manner. If the grain should
break at this stage in the latter stages of combustion no harm will result as the
projectile has then already proceeded a considerable distance along the bore and
the pressure behind it has fallen considerably.
The means employed for effecting the object of the invention are as follows:-
Moulds are prepared corresponding in form to the blocks of powder described
above and in these moulds gunpowder is consolidated by hydraulic or other
pressure.
In order that my said invention may be most fully understood and readily
carried into effect I will proceed to describe the Drawings.
DESCRIPTION OF THE DRAWINGS
Figure 1 is a side elevation and Figure 2 is a transverse section. Figure 3 is a
longitudinal section and Figure 4 is an end elevation of a block of gunpowder in 4
form prismatic with convex ends and with indentations on two opposite surfaces.
Figure 5 shows to a small scale two such blocks as they pack one on the other.
Figure 6 shows two ordinary prismatic blocks with flat ends similarly arranged.
At a. a. are seen spaces resulting from the convexity of the ends and these serve
as channels by which flame may pass for the instantaneous ignition of the charge
4

page_text: To produce these blocks gunpowder is compressed by hydraulic pressure in moulds
of corresponding form.
What I claim is :-
First Gunpowder moulded into blocks with indentations on two opposite faces
substantially as described.
Second Gunpowder moulded into prismatic blocks with convex ends and with
indentations on two opposite faces substantially as described.
In witness whereof I the said Thorsten Nordenfelt have hereunto set my hand
and seal this twelfth day of March in the year of our Lord One thousand eight
hundred and eighty four.
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