IMPROVEMENTS IN MOTIVE POWER ENGINES
Year: 1864

page_text: LETTERS PATENT to William Howe, of Clay Cross, near Chesterfield,
in the County of Derby, for the Invention of "IMPROVEMENTS IN MOTIVE
POWER ENGINES."
Sealed the 23rd August 1864, and dated the 22nd March 1864.
PROVISIONAL SPECIFICATION left by the said William Howe at the
Office of the Commissioners of Patents, with his Petition, on the 22nd
March 1864.
I, WILLIAM HOWE, of Clay Cross, near Chesterfield, in the County of
Derby, do hereby declare the nature of the said Invention for "IMPROVE-
MENTS IN MOTIVE POWER ENGINES," to be as follows:-
This Invention relates to a mode of relieving the ordinary slide valve
employed in steam and other motive power engine cylinders from pressure
to any practical extent without, increasing the rubbing surface, and for this
purpose it is proposed to apply two slide valves placed back to back
working over double ports, each set of ports being only half the area
required for any size of cylinder. Thus two valve faces with two sets of
ports merging into one port leading to each end of the cylinder would be
adopted, or the parts from the two faces may pass forward separately
into each end of the cylinder. On the back of each slide valve a cylindrical
projection is proposed to be cast, these projections are intended to be halved

page_text: into each other and accurately fitted. À recess is also turned on the outside
of each projection, and an india-rubber or metallic hoop is placed therein.
The frame in connection with the valve spindle may be made of wrought iron
or other metal, and must be accurately bored to fit the cylindrical projections,
and enclose the india-rubber or other hoop, keeping it securely in its place.
It is proposed to have holes through the back of the valves in order to allow
any leakage that may pass the india-rubber, or other hoop to escape into the
exhaust pipe. These holes may be increased in size to such an extent that
it would be totally unnecessary to have an exhaust passage round the back of
the steam chest. In such case the exhaust steam would pass directly through
the valves, and out at the exhaust pipe, which may be situate on one side of
the steam chest. It is proposed to place a spiral or other spring or springs
inside the cylindrical projection on the back of the valves for the purpose of
pressing them up to the faces of the cylinder should they at any time be
driven therefrom by water or compressed steam acting against the valve
faces. It is also proposed to have a relieving valve at each end of the
cylinder to counteract such a consequence, these relieving valves may be fixed
on the cylinder ends, or on branches cast on the cylinder for that purpose.
It will be seen if the area of the projection on the back of the valves were
increased, the weight thereon may be decreased to any extent; these pro-
jections on the back of the valves may be round, square, or any other shape,
but round is preferred on account of the greater ease of fitting up. A pair
of valves might be cast in one, and fitted accurately between the faces, which
might be inclined a little to ensure tightness. Or an adjustable wedge might
be placed between the two valves instead of the cylindrical or other projec-
tion to exclude the steam entirely from the backs of the valves, but the
cylindrical projection is preferred on account of its facility of adjusting itself
to, the valve faces when unequal expansion or contraction takes place in the
metals employed, as the entirely rigid form of valve would undoubtedly be
liable to expand more than the outer case and consequently stick and become
immovable.
The essential feature therefore of this Invention consists in having duplex or
double ports and valve faces, and one, two, or more valves to each cylinder, such
valves being connected together or otherwise in any manner to relieve them
from the pressure of the steam, water, air, or gas acting on their backs.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent; filed
by the said William Howe in the Great, Seal Patent Office on the
14th September 1864.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, WILLIAM
5 HOWE, of Clay Cross, near Chesterfield, in the County of Derby, send
greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Twenty-second day of March, in the year of our
Lord One thousand eight hundred and sixty-four, in the twenty-seventh year
of Her reign, did, for Herself, Her beirs and successors, give and grant unto
me, the said 'William Howe, Her special license that I, the said William
Howe, my executors, administrators, and assigns, or such others as I, the
said William Howe, tiny executors, administrators, or assigns, should at any
time agree with, and no others, from time to time and at all times thereafter
5 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 "IMPROVE-
MENTS IN MOTIVE POWER ENGINES," upon the condition (amongst others)
that I, the said William Howe, my executors or administrators, by an
instrument in writing under my hand and seal, or under the hand and seal of
one of them, 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 William Howe, do hereby declare
the nature of my 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, reference being had to the accompanying Drawings, and to the
letters and figures marked thereon, that is to say:-
My said Invention relates to a mode of relieving the ordinary slide valve
employed in steam and other motive power engine cylinders from pressure to
any practical extent, without materially increasing the rubbing surface. And
for this purpose it is proposed to apply two slide valves placed back to back,
working over double ports, each set of ports being only half the area required
for any size of cylinder. Thus two valve faces, with two sets of ports merging
into one port leading to each end of the cylinder would be adopted, or the ports
from the two faces may pass forward separately into each end of the cylinder.
Or the two valves and ports from the same may be so arranged that a full-

page_text: sized steam port may pass from one valve to one end of the cylinder, and
another full-sized steam port from the other valve to the opposite end of the
cylinder, each valve face having one steam port and one eduction port. On
the back of each slide valve a cylindrical projection is proposed to be cast,
these projections are intended to be halved into each other and accurately
fitted. A recess is also turned on the outside of each projection, and an
india-rabber or metallic hoop is placed therein. The frame in connection
with the valve spindle, may be made of wrought iron or other metal, and
'must be accurately bored to fit the cylindrical projections, and enclose the
india-rubber or other hoop, keeping it securely in its place. It is not
absolutely necessary to halve the projections on the backs of the valves
together. They may be placed back to back with a plain butt joint, allowing
a little room between for expansion. Over the joint a thin metallic hoop
may be placed when an india-rubber or other flexible hoop is used to prevent
the same being forced into the joint. It is proposed to have a free passage
or opening through the back of the valves, in order to allow any leakage that
may pass the india-rubber or other hoop to escape into the exhaust pipe.
This passage or opening may be increased in size to such an extent that it
would be totally unnecessary to have an exhaust passage round the back of
the steam chest. In such case the exhaust steam would pass directly through
the valves and out at the exhaust pipe, which may be situate on one side of
the steam chest. If requisite a spiral or other spring or springs may be
placed inside the cylindrical projection on the back of the valves for the
purpose of pressing them up to the faces of the cylinder, should they at any
time be driven therefrom by water or compressed steam acting against the
valve faces, or a relieving valve may be fitted on to each end of the cylinder
to counteract such a consequence; these relieving valves may be fixed on the
cylinder ends or on branches cast on the cylinder for that purpose. It will be
seen that if the area of the projection on the back of the valves were increased
the weight thereon may be decreased to any extent. These projections on the
back of the valves may be round, square, or of any other shape, but round is
preferred on account of the greater ease of fitting up. A pair of valves
might be cast in one, and fitted accurately between the faces, which might be
inclined a little to ensure tightness. Or an adjustable wedge might be
placed between the two valves instead of the cylindrical or other projec
tion to exclude the steam entirely from the backs of the valves, but the
cylindrical projection is preferred on account of its facility of adjusting itself
to the valve faces when unequal expansion or contraction takes place in the
metals employed, as the entirely rigid form of valve would undoubtedly be

page_text: liable to expand.more than the outer case, and consequently stick and become
immovable.
The essential feature therefore of my said Invention consists in having
duplex or double valve faces opposite to each other, and one or more valves
placed to work back. to back between the same, and connected together or
otherwise arranged so as to relieve them from the pressure of the steam,
water, air, or gas acting on their backs.
And in order that my said Invention may be fully understood, I shall
now proceed more particularly. to describe the same, and for that purpose
I shall refer to the several Figures on the Sheet of Drawings hereunto
annexed, the same letters of reference indicating corresponding parts in all the
Figures.
Fig. 1, of my Drawings represents a longitudinal section taken through
the centre of the steam chest, shewing the back of the valve, and the flexible
hoop also in section.; Fig. 2 is a longitudinal section taken at right angles
to Fig. 1, through the steam chest, and ports shewing the valves, india-
rubber and wrought iron or other metallic hoop, also in section; Fig. 3
is a cross section along the line A, B (Fig. 1), through the eduction
port, and Fig. 4 is a cross section along the line C, D (Fig. 2), through the
steam ports.
.
a, a, are two slide valves placed back to back, and encircled where they
join with an india-rubber or other hoop b, the whole being surrounded by a
wrought iron or other metallic frame c, to which the valve spindle d is con-
nected; e, e, and e³, e³, are the steam ports leading to each end of the
cylinder, and connected together by the passages f, f, and f, f (Fig. 1),
and shewn in cross section at Fig. 4; 9, 9, are the eduction ports commu-
nicating with the exhaust pipe h by the passage i (Figs. 1 and 3), and by
the opening through the backs of the valves, shewn in Figs. 2 and 3; k is
the steam pipe arranged to admit the steam to each end of the steam chest,
as shewn in Figure 2. It is evident so long as the joint between the backs of
the valves. is steam-tight, the pressure on the backs of the valves will be
reduced in proportion to the area of the part encircled by the india-rubber
or other hoop b. These valve faces may either be plain and flat, or circular,
so that the valves may reciprocate as a piston in a cylinder, or partially
revolve as a plug in a tap, the steam and eduction ports being cast to suit
circumstances.
Having now described and particularly ascertained the nature of my said
Invention, and the manner in which the same is or may be used or carried
into effect, I would observe in conclusion that what I consider to be novel

page_text: and original, and therefore claim as the Invention. secured to me by the herein-
before in part recited Letters Patent is,—
First, the general construction, arrangement, and combination of valves
and ports for steam, and other similar motive power engines, substantially in
the manner and for the purpose herein-before described.
Second, the application and use to and in the cylinders of steam and other
similar motive power engines of duplex or double valve forces, placed opposite
to each other, in combination with one or more valves arranged so as to work
back to back between such valve faces, substantially in the manner and for
the purpose herein-before described.
In witness whereof, I, the said William Howe, have hereunto set
my hand and seal, this Thirteenth day of September, One thousand
eight hundred and sixty-four.
WILLIAM HOWE. (L.S.).