An Improved Process for the Manufacture of Copper Cylinders, such as are Employed in Crusher Gauges for Registering the Pressures Developed in Ordnance and Firearms generally.
Year: 1898

page_text: An Improved Process for the Manufacture of Copper Cylinders, such
as are Employed in Crusher Gauges for Registering the Pressures
Developed in Ordnance and Firearms generally.
HENRY CAPEL LOFFT HOLDEN, Major Royal Artillery, Royal Arsenal, Woolwich,
do hereby declare the nature of this invention to be as follows:-
The object of my invention is to improve the processes of manufacture of copper
cylinders such as are employed in what are known as crusher gauges used for the
determination of pressures developed in ordnance and firearms generally.
Such cylinders cannot be too accurate in their dimensions.
Hitherto their production has been confined to hand processes and skilled labour
they having been turned to their correct diameter in a lathe and afterwards finished
by hand to the correct length; a slow and expensive process.
My improved process of manufacture ensures not only the greatest accuracy
in dimensions but simultaneously effects great economy and rapidity of production
by the employment of automatic machinery and unskilled labour. My improved
process is as follows; Round copper rod of a slightly smaller diameter than the
finished copper cylinder is cut into lengths in an automatic cutting off lathe, such
lengths being such that the cylinder so cut off is only very slightly heavier than
the completed copper cylinder, the cylinder is then adjusted by file or emery
wheel more exactly to the standard weight corresponding with the correct finished
dimensions. It is then pressed in an hydraulic press in a die which is exactly the
diameter the finished cylinder should be; such a pressure being applied that the
copper flows and fills the die; the cylinder is then removed from the die, and as it
is now of correct diameter and weight the length must also be correct.
The next process is to soften the copper, and this is effected by heating in a
furnace, preferably without the access of oxygen to the metal, to a given tempera-
ture and then cooling suddenly in water at a given temperature.
The copper cylinders made by this process will vary very slightly only from one
another in their physical properties.
Dated this 50th dor of duoust 1898

page_text: An Improved Process for the Manufacture of Copper Cylinders, such
as are Employed in Crusher Gauges for Registering the Pressure
Developed in Ordnance and Firearms generally.
I, HENRY CAPEL LOFFT HOLDEN, Major Royal Artillery, F.R.S., Royal Arsenal,
Woolwich, in the County of Kent, do hereby declare the nature of this invention
and in what manner the same is to be performed, to be particularly described
and ascertained in and by the following statement:
My invention relates to the manufacture of copper cylinders such as are
employed in what are known as crusher gauges used for the determination of
pressures developed in ordnance and firearms generally, and the efficiency of which
depends mainly upon the accuracy of the said coppers.
Hitherto the production of such cylinders has been confined to hand processes
carried out by skilled mechanics, the said cylinders having been turned from
copper rod to correct diameters in a lathe and afterwards finished by hand to the
correct length, both of which operations are slow and expensive, and even with the
greatest care it has been very difficult to obtain the required degree of accuracy.
The object of my invention is to ensure the greatest accuracy in dimensions and
at the same time effect great economy and rapidity of production and this
accomplish by the process hereinafter described which can be carried out by
unskilled labour.
In carrying out my process round copper rod of a diameter slightly smaller than
that which the finished copper cylinders are to have is cut into lengths in an
automatic cutting off lathe or machine, the length of each piece when cut off being
such that its weight is very slightly greater than the weight which the completed
copper cylinder is to possess, and then the weight of each piece is adjusted more
or less exactly to the standard weight corresponding with that of the finished
cylinder by filing it or by grinding it against an emery or other wheel, this opera-
tion requiring no care except so far as the weight is concerned.
The pieces of copper thus accurately adjusted as to weight are now individually
compressed between dies (the female of which is cylindrical and has exactly the
diameter of the finished cylinder) and subjected to such pressure that the copper
flows and fills the female die, with the result that the diameter and length are
corrected, the latter being dependent upon the correct diameter and weight.
The next and final step in the process is to soften the copper cylinders, and this
is effected by heating them in a furnace (and preferably a muffle so as to prevent
as far as possible the contact of oxygen with the metal) to a temperature of say
1000° Fahrenheit and then suddenly cooling them in water at a temperature of
say 65° Fahrenheit or whatever temperature may be required to produce the
desired annealing effect.
In practice it is found that the copper cylinders made by this process vary only
very slightly from one another in their physical properties, and are superior in this
respect to those hitherto made by hand processes.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed, I declare that what I
claim is
1. The process for the manufacture of copper cylinders such as are employed in
crusher gauges for registering the pressure developed in ordnance and firearms
generally, consisting in severing, by automatic mechanism, from a copper rod, of

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diameter slightly less than that which the finished cylinders are
to have, pieces of such length that their weight is slightly greater
that that of the finished cylinders, then adjusting these pieces to a
given weight and subsequently subjecting such lengths to the action
of dies in order to compress the said lengths longitudinally to the required length
and expand them laterally to the required diameter, and then softening the
cylinders so formed by heating them in a furnace and cooling them in water,
substantially as described.
2. The manufacture and use of copper cylinders for crusher gauges substantially
as hereinbefore described for the purpose specified.
Dated this 22nd day of December 1898
G. REDFERN & Co.,
4, South Street, Finsbury, London, Agent for the Applicant.