IMPROVEMENTS IN APPARATUS FOR THE MANUFACTURE OF PRISM, PELLET, PEBBLE, AND OTHER FORMS OF COMPRESSED GUNPOWDER
Year: 1880

page_text: LETTERS PATENT to Edward Lonsdale Beckwith and Thomas Bell Lightfoot,
both of Dartford, in the County of Kent, for an Invention of "IMPROVEMENTS
IN APPARATUS FOR THE MANUFACTURE OF PRISM, PELLET, PEBBLE, AND
OTHER FORMS OF COMPRESSED GUNPOWDER."
PROVISIONAL SPECIFICATION left by the said Edward Lonsdale Beckwith
& Thomas Bell Lightfoot at the Office of the Commissioners of Patents on
the 10th November 1880.
EDWARD LONSDALE BECKWITH and THOMAS BELL LIGHTFOOT, both of Dartford,
in the County of Kent. "IMPROVEMENTS IN APPARATUS FOR THE MANUFACTURE
OF PRISM, PELLET, PEBBLE, AND OTHER FORMS OF COMPRESSED GUNPOWDER."
In producing the various compressed forms of gunpowder, it is of great.
importance to ensure uniform density in the compressed pieces, and to be able to
vary somewhat that density. Our Invention relates to means of securing uniform
but variable density in the gunpowder compressed by such apparatus as may be
employed, whether the compression be effected by hydraulic pressure, or by the
direct action of cranks, cams, eccentrics, or other mechanism. For this purpose,
instead of rigidly attaching the compressing punches to the table head or bar by
which they are forced into the moulds, wo make them capable of moving as
plungers through packing into a hollow formed in such table head or bar, in which
any desired pressure of water or other liquid can be maintained. Thus, any one of
a number of the punches can yield more or less, being nevertheless subject in.
common with all the other punches to the pressure maintained in the hollow.
And this pressure by incans of an adjustable escape valve can be regulated as
desired. Either moving punches or butting punches, or both may be thus arranged.
according to the convenience of the machine in which they are employed, or when
both sets of punches move to compress the powder between them, either set or both
sets may be subjected as above described to the determined pressure.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
tho said Edward Lonsdale Beckwith & Thomas Bell Lightfoot in the Great
Seal Patent Office on the 9th May 1881.
EDWARD LONSDALE BECKWITH and THOMAS BELL LIGHTFOOT, both of Dartford,
in the County of Kent. "IMPROVEMENTS IN APPARATUS FOR THE MANUFACTURE
OF PRISM, PELLET, PEBBLE, AND OTHER FORMS OF COMPRESSED GUNPOWDER."
In producing the various compressed forms of gunpowder, it is of grent
importance to ensure uniform density in the compressed pieces, and to be able to
vary somewhat that density. Our Invention relates to means of securing uniform
but variable density in the gunpowder compressed by such apparatus as may be
employed, whether the compression be effected by hydraulic pressure or by the
direct action of cranks, cams, eccentrics, or other mechanism. For this purpose,
instead of rigidly attaching the compressing punches to the table head or bar by
which they are forced into the moulds, we make them capable of moving as
plungers through packing into a hollow formed in such table head or bar, in which
any desired pressure of water or other liquid can be maintained. Thus, any one of
a number of the punches can yield more or less, being nevertheless subject in
common with all the other punches to the pressure maintained in the hollow. And
this pressure by means of an adjustable escape valve, can be regulated as desired.
Either moving punches or butting punches or both may be thus arranged, according
to the convenience of the machine in which they are employed, or when both sets
of punches move to compress the powder between them, either set or both sets may
be subjected as above described to the determined pressure.
The accompanying Drawing represents a vertical section of a hydraulic press for
compressing pellets with our Invention applied thereto. In this form of press
there is a stationary table A, having through it a number of holes a which may be
cylindrical or of bexagonal or other section, according to the form desired for the
pellets, these holes constituting the moulds. Above the table is a follower B
carrying punches b, corresponding in form, number, and position to the moulds a.
This follower is moved by side rods C from the trunk piston D of the lower
hydraulic press.
Another follower E worked by the plunger F of the upper
hydraulic press has a corresponding set of punches e; these however are not rigidly
fixed to the follower, but are attached each to a separate plunger fitted to work
through packing in cylindrical holes opening into a cavity formed in the follower E.
This cavity is kept charged with water, oil, or other liquid to a pressure, such as is
equivalent to the desired compressive strain for the pellets. This pressure is
limited by a relief valve G loaded to the desired pressure, allowing excess of liquid
to escape into a receptacle. When the compression is relieved, springs under the
plungers, causing them to rise, the liquid that may have been discharged is drawn
back into the cavity. In cases where the main plungers D and F are subjected to
the definite pressure of an accumulator, which may be loaded to any desired
pressure, the relief valve G is unnecessary, but it is advisable to retain the check
valve and supply pipe, so that any escape by leakage may be made up for when
the punch plungers rise. In many cases the pellets have to be moulded with holes
through then. For this purpose quilly or core rods f are provided for each mould,
Each of these quills is attached at its base to tho under side of the mould tablo A
by a cross bar which works in a slot in the punch a. The punches & have holes
bored longitudinally in them to receive the quills f. The action of the press is as
follows: The upper follower B and its punches 6 being withdrawn by pressure
acting on the annular area of the piston D, and the lower follower E with its
punches e being lowered as shewn, the moulds a are charged with the powder, and
the pistons D and F being subjected to pressure on their full areas, the follower B

page_text: with its punches b descends, the punches entering the moulds a, and the follower E
with its punches c ascends. The powder is thus compressed in each mould between
the punches b and c, but each of the punches e has its pressure limited to that of
the liquid in the cavity E, and should the strain applied to compress the powder
above it tend to exceed the desired limit, the punch will yield. Thus every pellet,
whatever be the extent or character of the charge in the mould, undergoes the
same amount of compression, as determined by the fluid pressure maintained in the
cavity of E. When the compression has been effected, the follower B with its
punches bis raised by the hydraulic pressure acting on the annular area of the
piston D, then the lower follower E with its punches e is raised so as to push the
pellets out of the moulds, the quills f remaining stationary. The pellets being
removed from the upper surface of the mould tablo A, the follower E with its
punches e is again lowered, and the press is ready to receive another charge in its
moulds. Although we have described a pellet press worked by hydraulic pressure,
it is obvious that if the followers and punches were worked by cranks, eccentrics,
cams, or other mechanism, either set of the punches or both sets might be arranged
as we have described with reference to the punches c, each punch being attached to
a plunger subjected to a regulated fluid pressure maintained in a cavity of the
follower. Thus the punch instead of being rigidly connected to the follower is free
to yield, if the compressive strain in any mould should tend to exceed the desired
limit, and all the pellets, whatever be the amount or character of the powder
charge in the moulds, are thus subjected to a determined amount of compression.
Having thus described the nature of our Invention, and in what manner the
same is to be performed, we claim in respect of apparatus for the manufacture of
prisin, pellet, pebble, and other forms of compressed gunpowder,-
Subjecting each of the compressing punches separately to a determinable pressure
by attaching it to a hydraulic plunger, subject to the pressure of a fluid contained
in a cavity of the follower which carries the punches, substantially as and for the
purposes herein set forth.
In witness whereof, I, the said Thomas Bell Lightfoot, have hereunto set my
hand and seal, this Seventh day of May, in the year of our Lord One thousand
eight hundred and eighty one.