IMPROVEMENTS IN DIRECT- ACTING STEAM ENGINES
Year: 1870

page_text: LETTERS PATENT to Herbert Vosper, of Southsea, in the County of
Hampshire, Engineer, for the Invention of "IMPROVEMENTS IN DIRECT-
ACTING STEAM ENGINES."
Sealed the 20th December 1870, and dated the 7th October 1870.
PROVISIONAL SPECIFICATION left by the said Herbert Vosper at the
Office of the Commissioners of Patents, with his Petition, on the
7th October 1870.
I, HERBERT VOSPER, of Southsea, in the County of Hampshire,
Engineer, do hereby declare the nature of the said Invention for "Im-
PROVEMENTS IN DIRECT-ACTING STEAM ENGINES," to be as follows, that is to
say :-
The object of my improvements is to simplify the construction of the
direct-acting steam engine, whereby the full force of the steam is applied
until the piston has nearly completed its stroke.
To
carry out my Invention the slide valve is actuated by means of a
lever, one arm of which is suitably jointed to the rod of the slide valve,
and the other arm is connected to a rod working in the piston rod of the

page_text: engine made hollow through a great part of its length for that purpose;
the lever moves on a centre or fulcrum on a bearing attached to a
suitable part of the engine. At the upper end of the rod passing in the
hollow piston rod is fixed a collar, and when the piston of the engine
arrives at nearly the end of its stroke it strikes against this collar,
carrying it forward a short distance, and with it the rod fixed to one end
of the aforesaid lever, which thus moves on its centre, and consequently
moves the slide valve by means of its rod so as to cut off the steam from
one port and open the other port through which the steam now enters
driving back the piston, and the solid portion of its rod in returning
strikes against the said collar and moves the valve in the opposite
direction to that herein-before described, thus keeping up the motion
of the engine. The hollow piston rod is provided with suitable
buffers.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Herbert Vosper in the Great Seal Patent Office on
the 4th April 1871.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, HERBERT
VOSPER, of Southsea, in the County of Hampshire, Engineer, send
greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Seventh day of October, in the year of
our Lord One thousand eight hundred and seventy, in the thirty-fourth
year of Her reign, did, for Herself, Her heirs and successors, give and
grant unto me, the said Herbert Vosper, Her special licence that I, the
said Herbert Vosper, my executors, administrators, and assigns, or such
others as I, the said Herbert Vosper, my executors, administrators, and
assigns, should at any time agree 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 DIRECT-ACTING STEAM

page_text: ENGINES," upon the condition (amongst others) that I, the said Herbert
Vosper, my executors or administrators, by an instrument in writing
under my, or their, or one of their hands and seals, should particularly
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
immediately after the date of the said Letters Patent.
NOW KNOW YE, that I, the said Herbert Vosper, do hereby declare
the nature of my said Invention, and in what manner the same is to bo
performed, to be particularly described and ascertained in and by the
following statement, reference being had to the Drawing hereto annexed
and to the figures and letters marked thereon, that is to say:
The object of my improvements is to simplify the construction of the
direct-acting steam engine, whereby the full force of the steam is applied
until the piston has nearly completed its stroke.
To carry out my Invention the slide valve is actuated by means of a
lever, one arm of which is suitably jointed to the rod of the slide valve,
and the other arm is connected to a rod working in the piston rod of the
engine made hollow through a great part of it's length for that purpose;
the lever moves on a centre or fulcrum on a bearing attached to a
suitable part of the engine, and at the upper end of the rod in the hollow
piston rod is fixed a collar.
By this arrangement when the piston of the engine arrives at nearly
the end of its stroke it strikes against the collar, carrying it forward a
short distance, and with it the rod fixed to one end of the aforesaid lever,
which thus moves on its centre, and consequently moves the slide valve
by means of its rod so as to cut off the steam from one port and open
the other port, through which the steam now enters, driving back the
piston, and the solid portion of its rod in returning strikes against the
said collar and moves the valve in the opposite direction to that herein-
before described, thus keeping up the motion of the engine. The hollow
piston rod is provided with suitable buffers when required.
I employ an ordinary cylinder, piston, and slide valve.
My improvements are applicable to ordinary existing engines.
To make my Invention better understood I will proceed to describe
the same by reference to the accompanying Drawing, in which Figure 1

page_text: is a side elevation, and Figure 2 a section of a horizontal steam engine
constructed with my improvements.
a, a, is the cylinder; b, b, the piston, and c the slide valve, which are of
the ordinary construction; d is the lever, the upper end of which is
jointed at e to the rod f of the slide valve c, the lower end of the lever
being jointed at g to the rod h working in the piston rod i, i, and
having a collar m at the end; the lever d moves on a joint or centre
at k, on the bearing fixed in the cover of the cylinder. By this
arrangement the steam entering the cylinder at the port o would drive
the piston towards the other end of the cylinder, and when nearly at the
end of its stroke the solid part p of the piston rod i would strike against
the collar m of the rod h, moving it forward, and thereby cause the
lever d to move the rod f and slide valve c, by which the steam would
be cut off from the port o and the port opened, by which means the
piston is moved towards the other end of the cylinder, when the gland &
of the piston would strike the collar m, and again reverse the slide valve,
thus keeping up the motion of the engine.
A steam engine constructed with my improvements is specially
applicable for driving a pump by the piston rod being made of sufficient
length to form the pump rod.
Having now described my said Invention, and the manner of performing
the same, what I claim is, the improvements in direct-acting steam
engines, substantially as herein-before described and represented in the
accompanying Drawing.
In witness whereof, I, the said Herbert Vosper, have hereto set
my hand and seal, this First day of April, in the year of our
Lord One thousand eight hundred and seventy-one.