IMPROVEMENTS IN STEAM ENGINES
Year: 1855

page_text: PROVISIONAL SPECIFICATION left by the said Samuel Roberts at the
Office of the Commissioners of Patents, with his Petition, on the 5th
May 1855.
I, SAMUEL ROBERTS, of Hull, Smith, do hereby declare the nature of the
Invention for "IMPROVEMENTS IN STEAM ENGINES" to be as follows:-
This Invention has for its object a peculiar combination of parts of a steam
engine, whereby the power of the steam acting on the pistons is more directly
applied to the shaft or axis, and the number of parts necessary for constructing
a steam engine is reduced. For this purpose the steam cylinder is made
longer than is required for the ordinary constructions of steam engines, and in
place of using one piston therein, two pistons are employed, each of which is
moved to and fro within the cylinder a distance somewhat less than half the
length of the steam cylinder. The two pistons are connected together by a
plate or frame, having in it a slot to receive a wheel placed on the crank pin,
so that by the to and fro movements of the pistons motion is given to the
crank which is within the cylinder. The shaft or axis passes through the
cylinder. Steam ports are formed at each end of the cylinder, and they are
connected by the steam pipe from the boiler; the outer ends of such steam pipe
are connected with the condenser. In the steam pipe, and opposite the
entrances of the steam ports, two slide valves work which are on the same rod,
so that by the steam being introduced between them the pressure of the steam
on the valves is kept in a state of balance.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Samuel Roberts in the Great Seal Patent Office on the
3rd November 1855.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, SAMUEL
ROBERTS, of Hull, Smith, send greeting..
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Fifth, day of May, in the year of our Lord One
thousand eight hundred and fifty-five, in the eighteenth year of Ier reign,
did, for Herself, Her heirs and successors, give and grant unto me, the
said Samuel Roberts, Her special licence that I, the said Samuel Roberts,
my executors, administrators, and assigns, or such others as I, the said Samuel
Roberts, my executors, administrators, and assigns, should at any time ngree
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
STEAM ENGINES," upon the condition (amongst others) that I, the said Samuel
Roberts, by an instrument in writing under my hand and seal, should par-
ticularly 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 imme-
diately after the date of the said Letters Patent.
NOW KNOW YE, that I, the said Samuel Roberts, do hereby declare the
naturo of the 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 thereof (that is to say):-
This Invention has for its object a peculiar combination of parts of a steam
engine, whereby the power of the steam acting on the pistons is more directly
applied to the shaft or axis, and the number of parts necessary for constructing
a steam engine is reduced. For this purpose the steam cylinder is made
longer than is required for the ordinary constructions of steam engines, and in
place of using one piston therein, two pistons are employed, each of which is
moved to and fro within the cylinder a distance somewhat less than half the
length of the steam cylinder. The two pistons are connected together by a plate
or frame, having in it a slot to receive a wheel placed on the crank pin, so that
by the to and fro movements of the pistons motion is given to the crank which
is within the cylinder. The shaft or axis passes through the cylinder. Steam

page_text: ports are formed at each end of the cylinder, and they are connected by the
steam pipe from the boiler.
Having thus stated the nature of my said Invention, I will proceed to
describe more fully the manner of performing the same.
The Drawing annexed represents the section of a steam engine cylinder
arranged with two pistons therein, and with the driving shaft and crank,
according to my Invention. a, a, is the steam cylinder; b, b, are the two end
covers, in neither of which is shown any stuffing box for the passage of a piston
rod, but if it be preferred that the piston rod of the air or other pump should
be worked direct by the pistons or either of them, then the piston rod or rods
will be applied to the piston or pistons, and proper stuffing boxes made there-
fore to the cover or covers; c, c, is a framing which connects the action of the
pistons b', b. This framing is made in two parts, the one part being made
capable of being set up from time to time by set screws d, d. By this means
the slot or space e, e, in the frame c, c, is kept correct, notwithstanding the
wearing of the parts. f is the shaft of the engine, and g its crank, by which it
receives rotatory motion from the reciprocating of the two pistons 6', 6', in
the cylinder a, a. The shaft passes into, and if desired, may pass through, the
cylinder a, a, by a suitable opening or openings therein. h, i, are the steam
ways and ports. j is the exhaust passage. The valve may be of the ordinary
kind, or two valves may be used on the same rod, in which case the ports and
steam passages would have to be made accordingly, as is well understood.
Having thus described the nature of my said Invention, and the manner of
performing the same, I would have it understood that I do not claim any of
the parts separately, nor do I confine myself to the precise details; but what
I claim is, the mode herein described of constructing and combining the
parts of a steam engine.
In witness whereof, I, the said Samuel Roberts, have hereunto set my
hand and seal, this Second day of November, in the year of our Lord
One thousand eight hundred and fifty-five.
Witness,
HENRY ESNERT,
of Hull.
SAMUEL ROBERTS. (L.s.)