AN IMPROVEMENT IN METALLIC CARTRIDGE CASES AND APPARATUS FOR EFFECTING THE SAME
Year: 1881

page_text: PROVISIONAL SPECIFICATION left by George Kynoch at the Office of the
Commissioners of Patents on the 16th December 1881. A communication
from abroad by Arthur Butler of Munich in the Kingdon of Bavaria.
GEORGE KYNOCH of Witton in the County of Stafford. "AN IMPROVEMENT IN
METALLIC CARTRIDGE CASES AND APPARATUS FOR EFFECTING THE SAME." [A
communication from abroad by Arthur Butler of Munich in the Kingdom of
Bavaria.]
The case of a cartridge used for sporting purposes after being charged with
gunpowder and shot has its charge retained by a wad placed in the mouth of the
cartridge and secured by applying some adhesive substance or, when the cartridge
case is made of metal by bending or coning in its mouth. This Invention relates to
means of securing the wads in metallic cartridge cases without the use of any adhesive
substance or without having to bend or otherwise deform the mouth of the cartridge.
For this purpose there are formed at the mouth of the cartridge case a few threads
of a screw by indenting the thin metal of the case with a blunt point which is
pressed against the tube of the case and made to move longitudinally while the
case revolves. The screw thread thus indented by the pressure of the point against
the outside of the cartridge case projects inwards presenting at the mouth of the
cartridge an internal thread into which the wad being of yielding material becomes
engaged by turning it several times round while it is being pushed in. The wad
thus screwed in is held securely by the thread without liability to be shaken out
or otherwise displaced. The screw thread above described may be indented in a
manner similar to that in which a screw is cut in a lathe. A tool or apparatus
which is convenient for the purpose is of the following kind. A mandril with
reversing gear and clutch for driving it is mounted in a headstock and has cut on
its nose and also about its middle a thread of suitable pitch. A part nut attached
to a longitudinally sliding bar can be engaged with the middle thread, so that
according as the mandril tnrns in the one direction or the other the bar can be
caused to travel to or fro. The bar carries a block or holder from which the
indenting point projects near the screwed nose of the mandril and a handle is
provided by which this point can be advanced towards the mandril or retracted,
the same handle serving to engage or disengage the part nut and the reversing

page_text: clutch. In operating with this apparatus the mouth of the cartridge case is put on
the screwed nose of the mandril which loosely fits it and the handle is then moved
so as to press the indenting point against it, and as this movement of the handle
at the same time engages the clutch and the part nut, the mandril revolves and the
indenting point travels longitudinally indenting the thread on the cartridge case.
The handle being then moved so as to withdraw the indenting point and unclutch
the driving gear, the cartridge case with the thread indented on it is removed from
the mandril, and the mandril being reversed the sliding bar moves back presenting
the indenting point ready to operate on a succeeding cartridge case.