IMPROVEMENTS IN MORTARS
Year: 1860

page_text: LETTERS PATENT to William Krutzsch, of Chamber Street, Goodman's
Fields, E., Engineer, for the Invention of "IMPROVEMENTS IN MORTARS."
Sealed the 13th November 1860, and dated the 17th May 1860.
PROVISIONAL SPECIFICATION left by the said William Krutzsch at the
Office of the Commissioners of Patents, with his Petition, on the 17th
May 1860.
I, WILLIAM KRUTZSCH, of Chamber Street, Goodman's Fields, E., Engineer,
do hereby declare the nature of the said Invention for "IMPROVEMENTS IN
MORTARS," to be as follows:-
This Invention relates to certain improvements in the construction and
mode of using mortars, and in certain alterations in and additions to mortars as
at present constructed and used, and consists in cutting, turning out, or other
wise forming a groove of semicircular or other suitable section in the cylindrical
part or bore of a mortar, and in such position or portion of the length as shall
be in advance of the greatest diameter of the projectile or somewhat nearer to
the muzzle of the mortar. I form rings of lead or any other metal or composi-
tion of a suitable degree of hardness, and of a section suited to the groove
which has been formed in the mortar, and after inserting the charge and the
projectile I place the metal ring or grummet within the groove which has
been prepared to receive it. After igniting the charge, the explosive power of
the powder is accumulated until it proves sufficient to drive the projectile and

page_text: a portion of the metal ring through the bore, the measure of resistance to the
undue escape of the projectile being governed by the diameter or breadth of
the ring, and its hardness or ability to resist the shearing action. Thus I am
enabled to take full advantage of the entire explosive force of the powder, and
obtain a greatly increased flight of the projectile with the ordinary charge, and
a given size of projectile, or instead thereof, the same flight or distance of pro-
jection of a given size of projectile with a greatly reduced charge of powder.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said William Krutzsch in the Great Seal Patent Office on the
16th November 1860.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, WILLIAM
KRUTZSCH, of Chamber Street, Goodman's Fields, E., Engineer, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Seventeenth day of May, in the year of our Lord
One thousand eight hundred and sixty, in the twenty-third year of Her reign,
did, for Herself, Her heirs and successors, give and grant unto me, the said
William Krutzsch, Her special licence that I, the said William Krutzsch, my
executors, administrators, and assigns, or such others as I, the said William
Krutzsch, my executors, administrators, and assigns, should at any time
agree with, and no others, from time to time and at all times thereafter
during the term therein expressed, should and lawfully might make, use,
exercise, and vend, within the United Kingdom of Great Britain and Ireland,
the Channel Islands, and Isle of Man, an Invention for "IMPROVEMENTS IN
MORTARS," upon the condition (amongst others) that I, the said William
Krutzsch, my executors or administrators, by an instrument in writing under
my, or their, or one of their hands and seals, should particularly describe and
ascertain the nature of the said Invention, and in what manner the same was
to be performed, and cause the same to be filed in the Great Seal Patent Office
within six calendar months next and immediately after the date of the said
Letters Patent.
NOW KNOW YE, that I, the said William Krutzsch, do hereby declare the
nature of my said Invention, and in what manner the same is to be per-
formed, to be particularly described and ascertained in and by the following
statement in writing and accompanying Sheet of Drawings :-
This Invention relates to certain improvements in the construction and
mode of using mortars, and in certain alterations in and additions to mortars

page_text: as at present constructed and used, and consists in cutting, turning out, or
otherwise forming a groove of semicircular or other suitable section in the
cylindrical part or bore of a mortar, and in such position or portion of the
length as shall be in advance of the greatest diameter of the projectile or some-
what nearer to the muzzle of the mortar. I form rings of lead or any other
metal or composition of a suitable degree of hardness or softness, and of a
section suited to the groove which has been formed in the mortar, and after
inserting the charge and the projectile, I place the metal ring or grummet
within the groove which has been prepared to receive it, such metal ring or
grummet being either placed in by hand or otherwise forced in. I form such
rings or grummets by taking rods of the suitable metal, and of the required
section, and having cut them to the proper length, each end being bevilled
to any suitable angle, I prefer to bend or curve the rod into shape in tho
net of placing it in position in the groove, although they may be previously
prepared to the curve and circular dimensions of the mortar, if preferred.
After igniting the charge, the explosive power of the powder is accumulated
until it proves sufficient to drive the projectile and a portion of the metal ring
through the bore, the measure of resistance to the undue escape of the pro-
jectile being governed by the diameter or breadth of the rod or bar forming the
ring, and its hardness or ability to resist the shearing action; thus, I am
enabled to take full advantage of the entire explosive force of the powder,
and obtain a greatly increased flight of the projectile with the ordinary charge
of powder, and a given size of projectile, or instead thereof, the sanie flight or
distance of projection of a given size of projectile with a greatly reduced charge
of powder.
By employing the ordinary charge of powder with the ordinary weight of
projectile to be discharged from a mortar, I am, by the addition of my im-
provements, enabled to impart to such ordinary projectile the velocity and force
of a projectile of greatly increased weight and dimensions; and thus mortars
of smaller size may be employed for the purpose of throwing shells to greatly
increased distances, and by this means enabling the ordinary service mortars
to keep pace with the improved artillery practice effected by rifled ordnance.
In the accompanying Sheet of Drawings herounto annexed for the purpose
of illustrating my Invention for improvements in mortars, as herein-before set
forth, Figure 1 is an external elevational view of a mortar proportioned and
constructed generally similar to those in ordinary use, but having the addition
of a ring around the mouth or muzzle, which may be provided in new mortars,
or may be added to mortars already constructed by being shrunk thereonto;
and, although it need not necessarily be provided in mortars constructed

page_text: according to my present Invention, yet I have shewn it as a means of holding
or retaining the mechanical means or apparatus for forcing into position the
shell or projectile and the metal ring or grummet, as the use of such apparatus
may in certain cases be deemed necessary. The internal bore and the groove
formed according to my present Invention are shewn in dotted lines. In this
Figure a circular groove is shewn for the reception of the metal ring or
grummet, the dimensions and form of which, however, may be varied, as
herein-before stated.
Figure 2 is a longitudinal section of the mortar, shewn in Figure 1, taken
through the centro thereof at right angles to the axis of the trunnions. The
groove before referred to is here shewn as being occupied or filled with the
metal ring or grummet, which is placed or forced into the groove or recess
formed in the bore of the mortar, such groove and metal ring or grummet
being in this case, by way of variation, shewn of a different shape to that given
in Figure 1.
Figure 3 shews a detached elevational view of the metal ring or grummet,
which, as before described, is placed or forced into the cavity previously formed
in the bore of the mortar to receive it.
Figure 4 shews a detached view of a contrivance I have designed for the
purpose of charging the mortar, and forcing the metal ring or grummet there-
into with increased pressure whenever necessary.
Figures 5, 6, and 7, illustrate some of the variations which may be made in
the form and dimensions of the groove formed in the bore of the mortar and
of the metal ring or grummet to be placed or forced thereinto.
In the several views in the accompanying Drawing herein-before referred to,
a is the groove or cavity formed in the bore or cylindrical part of the mortar,
and which may be of any suitable form in section; b is the metal ring or grummet,
which is placed or forced into the groove or cavity a formed in the bore of the
mortar to receive it, such metal ring or grummet being of a corresponding
form to the groove to which it is to be adapted.
Having now described my Invention, and illustrated the same in the accom-
panying Drawing by its applications, as shewn therein, and having also shewn
a means of charging and forcing into position by mechanical means or apparatus
the metal ring or grummet, although I do not claim the said mechanical
contrivance as part of my present Invention, what I claim is,
First, cutting, turning out, or otherwise forming a groove of semicircular or
other suitable section in the cylindrical part or bore of mortars, in such position
or portion of the length of the bore as shall be in advance of the greatest
diameter of the projectile, for the purpose of holding or retaining therein a

page_text: ring of lead or any other metal or composition, for the purpose of resisting the
too early or the too ready discharge of the projectile from the bore of the
mortar, and thereby taking advantage of the full explosive force of the gun-
powder or other explosive mixture.
Second, the use or employment of rods or rings of lead or other metal or
composition of any suitable section and degree of hardness or softness in com-
bination with a groove turned or otherwise formed in the cylindrical part or
bore of the mortar, as herein-before described, and for the purpose herein-
before set forth.
Third, the means and method, herein-before described, of increasing the
flight of a projectile of a given weight or size with the ordinary charge of
powder from mortars.
Fourth, the means or methods herein described of varying or controlling or
regulating the intensity of the explosive force behind a projectile, and of
increasing the flight of such projectile, and of imparting to it the velocity and
force due to a projectile of greater weight, by interposing a ring or grummet
of material which is submitted submitted to a shearing or cutting action during
the passage or escape of the projectile, as herein-before described.
In witness whereof, I, the said William Krutzsch, have hereunto set
my hand and seal, the Fifteenth day of November, in the year of our
Lord One thousand eight hundred and sixty.
WILLIAM KRUTZSCH. (L.s.)
Witness,
EDWP. HY. MAY,
Clerk to Messrs. Atchison & Hathaway, Sol".,
38, Lincoln's Inn Fields, London.