Improvements in Gas Checks for Projectiles.
Year: 1885

page_text: Improvements in Gas Checks for Projectiles.
We, CHARLES KEIR FARQUHARSON, of 34, Hereford Square South Kensington
Gentleman, and RICHARD RUSSELL GUBBINS, of 17 Park Road, New Cross in the
county of Kent, Gentleman, do hereby declare the nature of our said invention for
"IMPROVEMENTS IN GAS CHECKS FOR PROJECTILES," to be as follows:-
Our invention has for its object means of making bands or rings of copper or
other suitable metal for projectiles now used in rifled ordnance, and also for
attaching the said bands or rings immovably to the said shot, so that they
unfailingly impart spiral motion to it from the grooves in the barrel, and also
effectually close, any outlet through which the products of combustion might escape
between the shot and barrel aforesaid.
We make the gas check by preference of copper which we take in the form of
a flat narrow riband of sufficient length to encircle the shot. This we bend by
means of dies or fluted rollers, so as to form a shallow trough resembling the stave
of a cylindrical barrel. We bend this around the shot by any suitable means with
its hollow side inside, in an undercut groove which we have previously prepared for
it, and then by rollers or hammering we flatten out the curvature before described
which process expands it in the direction of its width so as to completely fill the
undercut groove in the shot. We continue to roll or hammer it until it comes
together at the joint so as to close the same thoroughly.
In making the groove in the shot we prefer to make the same serpentine, as this
shape holds the gas check much firmer than an ordinary straight groove would do.
As the spiral strain transmitted by the gas check from the grooves of the barrel is
very sudden and of great force it frequently turns or breaks off the gas checks
fastened in the usual way, round on the shot, before it has time to receive the
rotative impulse needed to accelerate flight. This we consider cannot happen when
the ring is forced into a serpentine groove.
WALTER A. BARLOW,
6, St. Paul's Churchyard, E.C.

page_text: We CHARLES KEIR FARQUHARSON of 34 Hereford Square South Kensington
and RICHARD RUSSELL GUBBINS of 17 Park Road New Cross in the county of
Kent, Gentlemen do hereby declare the nature of our invention for "IMPROVE-
MENTS IN GAS CHECKS FOR PROJECTILES" and in what manner the same is to be
performed, to be particularly described and ascertained in and by the following
statement:
This invention relates to certain improvements in gas checks for shot or
projectiles the object being to make bands for rings, of copper or other suitable
metal, to apply to projectiles such rings, (as are now used in rifled ordnance) and
for attaching the said bands or rings immovably to the said shot so that they shall
unfailingly impart to the shot or projectile the spiral or rotatory motion from the
grooves or rifling of the barrel and to effectually close any outlet through which
the products of combustion of the charge or powder might escape between the shot
or projectile and barrel.
We make the gas check by preference of copper (but of metal approved) in form
of a flat riband of sufficient length to encircle the shot or projectile; and this riband
is to be bent by means of dies or fluted or grooved rollers so as to form the riband
as a shallow trough approximately of form of a stave of a cylindrical barrel. This
fluted riband is bent around the shot by any suitable means with its hollow side
inwards and lying (before the rolling or hammering process) in the straight lines of
the undercut groove, which shall have been previously prepared for it. By the
rolling or hammering process or similar means the said riband shall then be forced
and laid into the groove of the shot or projectile so as to flatten out the curvature
before described which process will expand the riband in the direction of its width
so as to completely fill the undercut groove or depressions therein previously
provided in the groove of the shot and so that a continuous projecting ring of
metal shall be exposed above the line of the circumference of the shot to form the
gas-check ring.
The rolling or hammering of the ring is continued until the ends of the riband
come together at the extremities and form joint so as to close the same thoroughly
as a butt joint and weld or lap joint, and weld or butt and lap joint.
.
The bands for forming the ring are cut to the length sufficient for encircling the
shot or projectile and to lap or butt or to butt and lap.
In making the groove in the shot the lines of the outer portion of such groove
are parallel to each other and under this portion of this invention the undercut,
portions of the groove are made otherwise than in a straight line that is to say are
made with dwells along the side or alternately on either side of the groove or are
made serpentine this sinuosity of the undercut portion serving to receive by the
pressure, expressed and underlying portions of the metal of the riband or ring, thus
holding the gas check much more firmly and securely than an ordinary straight
undercut groove can do. This portion of this invention may be employed in
applying the ordinary ring of copper or metal the sinuous form or irregular
configuration of the undercut serving similar purpose in either case. There may

page_text: also be employed in combination with the sinuous undercut radial dwells which
may or may not be fitted with metal plugs in combination with the curved section
of riband or of the ring.
As the spiral strain transmitted to the gas-check from the grooves of the barrel
is very sudden and of great force it frequently turns or breaks off the gas checks
(fastened in the usual way around the shot) before it has time to receive the
rotative impulse needed for accurate flight. This shifting of the gas check ring
around the shot is prevented from taking place when the riband or ring is forced
into the serpentine or irregular undercut groove according to this invention.
In the drawings annexed hereto :—
Fig. 1 is a side view of a projectile fitted according to this invention. Fig. 2 is
an end view. Fig. 3. is a horizontal central section of Fig. 1; and Figs. 4 and 5
show respectively side view and end view of rollers for rolling the ring into the
groove of the projectile. Figs. 54 and 5B show sections of the riband and Fig. 5°
shows convenient form of butt and lap (scarf) joint for the extremities of the length
of riband which extremities come together in the rolling process and the ends of
the riband may be secured by a counter-sunk headed screw as shown, but practically
the pressure in laying in the ring will be found sufficient.
In the drawings a is the shot, bis the gas check ring, the line of the under-cut
being shown by dotted lines c, are the rolls employed which said rolls are to be
understood as being mounted in proper bearings for giving the proper amount of
nip and pressure to the riband shown in Fig. 5. Figs. 5%, and 5b, show sections of
the riband or ring of the arched form to enable the riband or ring to enter the
straight lines of the groove, and yet admit of the metal thereof being in sufficient
quantity or bulk to become expressed or flattened out into the sinuous or recessed
undercut. The section Fig. 5b is provided at d, with a feather, and when so used
radial dwells will be made in the bottom face of the groove, and by the pressure
corresponding portions of the feather d, will become pressed into such dwells so as
to form retaining plugs of the riband or ring. In the diagram Fig. 5°, is shown
a convenient form for lap and butt joint of the ends of the riband forming the gas
check ring, e, being a countersunk headed screw.
Having now particularly described, and ascertained the nature of our said
invention and in what manner the same is to be performed we declare that what
we claim is
Firstly. The improvements in gas check rings for shot or projectiles consisting of
the varied form of undercut for purpose of forming retaining pieces of said rings
within the groove when the said ring shall have been pressed or forced therein as
herein specified.
Secondly. For gas check rings of shot or projectiles the combination of the riband
of metal with the undercut groove, as and for the purpose herein set forth..
Thirdly. The employment of a riband of metal of section substantially as shown
and described for pressing or rolling the said piece into the undercut of a gas check
ring groove provided with recessed dwells or hollows, as and for the purpose herein
set forth.
Do
1001