IMPROVEMENTS IN COMPOUND HIGH AND LOW PRESSURE STEAM ENGINES."
Year: 1872

page_text: LETTERS PATENT to Henri Bertieaux, of Antwerp, in the Kingdom
of Belgium, for the Invention of "IMPROVEMENTS IN COMPOUND HIGH
AND LOW PRESSURE STEAM ENGINES."

page_text: pressure cylinder, and open to it. Each cylinder is fitted with a piston,
and the two pistons are connected together by a rod. A piston rod from
either piston passes through a stuffing, box in the end of the cylinder,
and gives motion by a connecting rod or otherwise to the crank.
In some cases there may be a piston rod through both ends, as when
one is required for working an air pump or for other purposes.
Each of the cylinders is fitted with a D slide, working within a slide
jacket, and the two slides are so arranged that they are connected by one
rod so as to work simultaneously; or instead of two slides so connected
together, one slide may be employed, the ports over which it works
being suitably arranged for the passage of steam as required. The high-
pressure steam from the boiler is admitted to act on one side of the
smaller piston, the steam on the opposite side of the larger piston being
then free to escape by the exhaust passage. Thus the pistons are caused
to make their stroke in the one direction.
As the pistons approach the end of this stroke the supply of high-
pressure steam from the boiler is cut off by the slide, and a communi-
cation is effected between the one end of the small cylinder and the
opposite end of the large cylinder, the large cylinder being at the same
time cut off from the exhaust. The steam which had worked the small
piston is thus allowed to expand into the larger cylinder, where it acts
on the piston of larger area and causes the pistons to perform their return
stroke, when the action is repeated. Air holes are provided in the end
of the larger cylinder next the smaller cylinder, so as to permit the free
passage of air into and out from the space between the two pistons, and
thereby to avoid the alternate dilatation and compression to which the
air contained in that space would be subject at alternate strokes of the
'pistons.

page_text: .
1
+
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Twenty-fourth day of January, in the year of
our Lord One thousand eight hundred and seventy-two, in the thirty-'
fifth year of Her reign, did, for Herself,, Her heirs and successors, give
and grant unto me, the said Henri Berticaux, Her special licence
that I, the said Henri Bertieaux, my executors, administrators, and'
assigns, or such others as I, the said Henri Bertieaux, 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
COMPOUND HIGH AND LOW PRESSURE STEAM ENGINES," upon the condition
(amongst others) that I, the said Henri Bertieaux, 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.
'

page_text: In some cases there may be a piston rod through both ends, as when
one is required for working an air pump or for other purposes.
Each of the cylinders is fitted with a D slide, working within a slide
jacket, and the two slides are so arranged that they are connected by one
rod so as to work simultaneously; or instead of two slides so connected
together, one slide may be employed, the ports over which it works
being suitably arranged for the passage of steam as required. The high-
pressure steam from the boiler is admitted to act on one side of the
smaller piston, the steam on the opposite side of the larger piston being
then free to escape by the exhaust passage. Thus the pistons are caused,
to make their stroke in the one direction.
As the pistons approach the end of the stroke the supply of high-
pressure steam from the boiler is cut off by the slide, and a communi-
cation is effected between the one end of the small cylinder and the
opposite end of the large cylinder, the cylinder being at the same time
cut off from the exhaust. The steam which had worked the small
piston is thus allowed to expand into the larger cylinder, where it acts
on the piston of larger area and causes the pistons to perform their return
stroke, when the action is repeated. Air holes are provided in the end
of the larger cylinder next the smaller cylinder, so as to permit the free
passage of air into and out from the space between the two pistons, and
thereby to avoid the alternate dilatation and compression to which the
air contained in that space would be subject at alternate strokes of the
nistons
Fig. 1 represents a section of a double cylinder and slides for a com-
pound engine arranged and constructed according to my Invention.
A is the high-pressure cylinder, which is by preference cast in one piece
with the low-pressure cylinder B. Each of the cylinders is provided
with a slide jacket marked respectively a and b, with their slides C and
D connected by a rod E. The exhaust port of the slide C is connected
by a passage f with the jacket b, so that the steam, after having acted
on the upper side of the smaller piston in A, is conveyed to act on the
under side of the larger piston in B, finally escaping by the eduction
passage d. Holes 9 are provided for the passage of air to and from the
space between the two pistons.

page_text: Fig. 2 represents a modification wherein one slide H serves for both.
cylinders, the eduction port of the smaller cylinder forming the induc-
tion port of the larger cylinder, which has its eduction passage d.
Passages 9, 9, are provided for air to and from the space between the
pistons.
Having thus described the nature of my Invention, and in what
manner the same is to be performed, I claim,―
First. The arrangement and construction of cylinders for compound
engines having their slides connected by a rod and holes for the passage ·
of air, substantially as described in reference to Fig. 1.
Second. The arrangement and construction of cylinders for compound
engines with one slide common to both cylinders and holes for passage
of air, substantially as described in reference to Fig. 2.
In witness whereof, I, the said Henri Bertieaux, have hereunto
set my hand and seal, this Ninth day of July, in the year of our
Lord One thousand eight hundred and seventy-two.