Improvements in Steam Engines.
Year: 1898

page_text: Improvements in Steam Engines.
We, JOHN HADFIELD STREET, Engineer, MARK HEATON ROBINSON, Engineer,
and MATTHEW HENRY PHINEAS RIALL SANKEY, Captain R.E. (retired), all of
Victoria Works, Rugby, in the County of Warwick, do hereby declare the nature
of this invention to be as follows:-
In central-valve engines of the type known as the Willans engine, in which
it is preferred to admit the steam to the cylinder, if there be only one over cach
crank, or to the upper cylinder, if there be more than one, by a separate admission
valve independent of the central-valve, we adopt a particular arrangement of
the central-valve, and of the hollow piston-rod, to enable us to dispense with
carrying the hollow piston-rod through the end of the cylinder into the steam
chest, which would otherwise be necessary in order to obtain a sufficient pressure
upon the line of valves, to ensure their being held down "in constant thrust,"
notwithstanding the effect of inertia upon them.
We form the upper piston of the line of piston valves (which serves as an
exhaust valve only) with a very deep hollow body, into which enters a tube or
trunk depending centrally from the cylinder cover, and working steam-tight in
the hollow valve-body, by means of a gland or packing rings or otherwise. The
parts are so proportioned that when the valve is at the lowest part of its stroke
the tube or hanging-trunk still enters the gland or packing rings. The tube or
hanging trunk communicates by a hole or port at its top with a steam chest in or
above the cylinder cover, which may be covered by a valve which alternately
opens and closes communication. The valve opens at an appropriate point in the
up-stroke of the central-valve, to cushion the latter towards the end of its up-
stroke, and closes at an appropriate point upon the down-stroke.
In cases where a rotating admission valve is used, such as is described in
another application of this date made by us, the admission and cut off of the
steam supply to the hanging trunk can be effected by a port in such valve,
appropriately placed and shaped.
It is not essential that steam be alternately admitted to, and cut off from,
the inside of the hanging-trunk and of the hollow piston-valve body. Those
spaces may be in permanent communication with the steam chest, in which case
the downward pressure on the line of piston-valves is constant. By making the
supply of steam intermittent the downward pressure can be removed or lessened
at times when it is not required, and the pressure can if necessary be raised, at
certain times, above that in the steam chest, by compression of the steam in
the hollow valve-body, as the latter rises.
Dated this 18th day of November 1898
JOHN H. STREET.
MARK H. ROBINSON.
M. H. P. R. SANKEY.

page_text: Improvements in Steam Engines.
We, JOHN HADFIELD STREET, Engineer, MARK HEATON ROBINSON, Engineer,
and MATTHEW HENRY PHINEAS RIALL. SANKEY, Captain R.E. (retired), all of
Victoria Works, Rugby, in the County of Warwick, do hereby declare the nature
of this invention, and in what manner the same is to be performed, to be par-
ticularly described and ascertained in and by the following statement:-
-
This invention relates to central valve engines of the type known as the Willans
engine, in which steam is admitted to the cylinder, if there be only one over
each crank, or to the upper cylinder, if there be more than one, by a separate
admission valve independent of the central-valve, and the invention has for its
object a particular arrangement of the central-valve, and of the hollow piston
rod, which make it unnecessary to carry the hollow piston rod through the end
of the cylinder into the steam chest, as would otherwise have to be done in order
to obtain a sufficient pressure upon the line of valves, to ensure their being held
down "in constant thrust," notwithstanding the effect of inertia upon them.
The drawing is a longitudinal central section of the upper part of the engine.
A is the upper cylinder, B the piston in it and C the hollow piston rod, all of
the usual type.
The upper piston a of the line of piston valves (which serves as an exhaust
valve only) is formed with a very deep hollow body, into which enters a trunk b
depending centrally from the cylinder cover c, and working steam-tight in the
hollow valve-body, by means of a gland or packing rings d or otherwise. The
parts are so proportioned that when the valve a is at the lowest part of its stroke
the hanging trunk b still enters the gland or packing rings d. The hanging
trunk communicates by a hole or port 61 at its top with a steam chest e in or
above the cylinder cover c which may be covered by a valve f which alternately
opens and closes communication. The valve opens at an appropriate point in
the up-stroke of the central valve, to cushion the latter towards the end of its
up-stroke, and closes at an appropriate point upon the down-stroke.
In cases where a rotating admission valve is used, such as is described in
another application of this date made by us No. 24459 the admission and cut-off
of the steam supply to the hanging-trunk can as shewn in the drawing he effected
by ports in such valve, appropriately placed and shaped.
It is not essential that steam be alternately admitted to, and cut off from,
the inside of the hanging trunk band of the hollow piston valve body. Those
spaces may be in permanent communication with the steam chest e in which case
the downward pressure on the line of piston-valves is constant. By making the
supply of steam intermittent the downward pressure can be removed or lessened
at times when it is not required, and the pressure can if necessary be raised, at
certain times, above that in the steam chest, by compression of the steam in
the hollow valve-body, as the latter rises.
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:-
1. In engines of the type known as the Willans engine having a piston valve
working endwise within a hollow piston rod, the forming a deep hollow in the
end of the piston valve and causing a tube or trunk extending inwards from the
end cylinder cover to pass steam tight into this hollow such tube or trunk being
also made to communicate by a hole or port at its outer end with the steam
chest.

page_text: 2. The combination of a cylinder, a cylinder cover, a piston in the cylinder, a
hollow piston rod fixed to the piston, a hollow piston valve in the rod, a hollow
trunk inside the piston valve and fixed to the cylinder cover and a valve for
admitting steam to the hollow trunk.
3. The combination of a cylinder, a cylinder cover, a steam chest, a piston in
the cylinder, a hollow piston rod fixed to the piston, a hollow piston valve in the
rod, a hollow trunk inside the piston valve and fixed to the cylinder cover and a
rotating valve outside the cylinder cover for admitting steam from the steam chest
to the hollow trunk as well as for admitting steam to the cylinder.
4. Steam or other elastic fluid engines arranged substantially as herein before
described and illustrated in the drawing annexed.
11 1011
1000
JOHN HADFIELD STREET.
MARK H. ROBINSON.
MATTHEW HENRY PHINEAS RIALL SANKEY,