IMPROVEMENTS IN THE CONSTRUCTION OF MOTIVE POWER ENGINES AND PUMS
Year: 1867

page_text: LETTERS PATENT to Emory McClintock, of the Langham Hotel, in the
County of Middlesex, Gentleman, for the Invention of "IMPROVEMENTS IN
THE CONSTRUCTION OF MOTIVE POWER ENGINES AND PUMS"
Sealed the 22nd November 1867, and dated the 21st June 1867.
PROVISIONAL SPECIFICATION left by the said Emory McClintock at the
Office of the Commissioners of Patents, with his Petition, on the
21st June 1867.
I, EMORY MCCLINTOCK, of the Langham Hotel, in the County of Middlesex,
Gentleman, do hereby declare the nature of the said Invention for "IMPROVE-
MENTS IN THE CONSTRUCTION, OF MOTIVE-POWER ENGINES AND PUMPS," to be as
follows:-
This Invention relates, to a peculiar construction of double cylinder engines
and pumps by which the piston; of each cylinder, is made to act as a four-way
distribution valve for the other cylinder.
Valvular pistons have been heretofore employed in constructing engines
and pumps in which the piston acts as a valve for the same cylinder.
In another arrangement a series of four or more single-acting cylinders are
employed, and in each of these the piston acts as a valve for the next succeeding
cylinder.
The novelty of my Invention is that I employ a double-acting cylinder and
piston serving also respectively as valve box and valve in combination with

page_text: one other similar cylinder with its piston. The two cylinders and their pistons
are so arranged that the piston of each cylinder shall act as a valve to govern
the distribution of steam or other fluid or liquid for the other cylinder. The
pistons of the two cylinders are connected together either by a shaft with
cranks, or excentrics, or by any other ordinary mechanical device, so that one
of them shall have completed its stroke when the other is at or near half-stroke,
and vice versa. I prefer to employ pistons and cylinders nearly similar in
size and arrangement, although such resemblance is not by any means essential.
Besides the ports or openings for its own supply and exhaust (which com-
municate with certain of the ports of the other cylinder) each cylinder has
four or more additional openings of any convenient shape and position, except
that these additional openings cannot be placed in the ends of the cylinder.
One or more of these additional openings communicates with the supply pipe,
one or more with the exhaust pipe, one or more with the upper or first chamber
of the other cylinder, and one or more with the lower or second chamber of
the same. The piston is of such length as to keep these additional openings
separated at all points of its stroke from any communication with the chambers
of its own cylinder above and below it, and also so that when at the middle of
its stroke there shall be no passage for the steam (or at least for any con-
siderable quantity) through these openings in any direction. Passages are
made through or around the piston, and are so arranged that when it moves
in one direction from the central position and until it returns to the same
position there shall be communication for the passage of steam between the
above-mentioned supply port or ports or any of them and the above-mentioned
port or ports communicating with the upper or first chamber of the other
cylinder or any of them, and also between the above-mentioned port or ports
communicating with the lower or second chamber of the other cylinder or any
of them and the above-mentioned exhaust port or ports or any of them, thus
rausing the piston of the other cylinder to make a complete stroke. When
the piston moves in the other direction from the central position, and until it
returns to the same position, communications.the reverse of the above will be
established and will produce the return stroke of the piston of the other
cylinder. Conversely the other cylinder with its piston is constructed upon the
same principles so as to regulate the distribution of steam for the cylinder first
mentioned.
A convenient reversing arrangement consists in the addition of a valve or
valves by which the steam may be made to flow in the opposite direction
through the engine.

page_text: The above mode of construction, though referring especially to the use of
steam, is also applicable to other motive-power engines and to pumps.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Emory McClintock in the Great Seal Patent Office on the
21st December 1867.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, EMORY
MCCLINTOCK, of the Langham Hotel, in the County of Middlesex, Gentleman,
send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Twenty-first day of June, in the year of our Lord
One thousand eight hundred and sixty-seven, in the thirty-first year, of Her
reign, did, for Herself, Her heirs and successors, give and grant unto
me, the said Emory McClintock, Her special licence that I, the said Emory
McClintock, my executors, administrators, and assigns, or such others as I, the
said Emory McClintock, 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 "IMPROVE-
MENTS IN THE CONSTRUCTION OF MOTIVE-POWER ENGINES AND PUMPS," upon the
condition (amongst others) that I, the said Emory McClintock, 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 Emory McClintock, do hereby declare
the nature of my said Invention, and in what manuer the same is to be
performed, to be particularly described and ascertained in, and by the following.
statement, reference being had to the Drawing hereunto annexed, and to the
letters and figures marked thereon (that is to say):-
.
"
This Invention relates to a peculiar construction of double cylinder engine
and pump by which the piston of each cylinder is made to act as a four-way.
distribution valve for the other cylinder.

page_text: Valvular pistons have been heretofore employed in constructing engines
and pumps in which the 'pistou acts as a valve for the same cylinder.
In another arrangement a series of four or more single-acting cylinders
are employed, and in each of these the piston aets as a valve for the next
succeeding cylinder..
The novelty of my Invention is that I employ a double-acting cylinder
and piston serving also respectively as valve box and valve in combination
with one other similar cylinder with its piston. The two cylinders and their
pistons are so arranged that the piston of each cylinder shall act, as a valve
to govern the distribution of steam or other fluid or liquid for the other
'cylinder. The pistons of the two cylinders are connected together either by a
shaft with cranks or excentrics or by any other ordinary mechanical device,
'so that one of them shall have completed its stroke when the other is at or
near half stroke, and vice versa. I prefer to employ pistons and cylinders
'nearly similar in size and arrangement, although such resemblance is not by
any means essential. Besides the ports or openings for its own supply and
exhaust (which communicate with certain of the ports of the other cylinder)
each cylinder has four or more additional openings of any convenient shape
and position, except that these additional openings- cannot be placed in the
ends of the cylinder; one or more of these additional openings will communicate
with the supply pipe, one or more with the exhaust pipe, one or more with the
upper or first chamber of the other cylinder, and one or more with the lower
or second chamber of the same. The piston is of such length as to keep these
additional openings separated at all points of its stroke from any communica-
tion with the chambers of its own cylinder, above and below it, and also so shaped
that when at the middle of its stroke there shall be no passage for the steam
(or at least for any considerable quantity) through these openings in any
irection. Passages are made through or around the piston, and are so
arranged that when it moves in one direction from the central position and
until it returns to the same position 'there shall be communication for the
passage of steam between the above-mentioned supply port or ports or any of
them and the above-mentioned port or ports communicating with the upper or
first chamber of the other cylinder, or any of them, and also between the above-
mentioned port or ports communicating with the lower or second chamber
of the other cylinder, or any of them, and the above mentioned exhaust port or
ports, or any of them, thus causing the piston of the other cylinder to make a
complete stroke. When the piston moves in the other direction from the
central position, and until it returns to the same position, communications the

page_text: reverse of the above will be established, and will produce the return stroke of
the piston of the other cylinder. Conversely the other cylinder with its piston
is constructed upon the same principles so as to regulate the distribution of
steam for the cylinder first mentioned.
A convenient reversing arrangement consists in the addition of a valve or
valves by which the steam may be made to flow in the opposite direction
through the engine.
The above mode of construction, though referring especially to the use of
steam, is also applicable to other motive-power engines and to pumps.
1
It must be understood that by the word "stroke" I mean the passage
of the piston in one direction only; that by the word "length" I mean length
in the direction of the stroke of the piston, except when speaking of cranks
and connecting rods; and that in using the word "cylinder "I do not confine
myself to vessels mathematically cylindrical in shape.
The accompanying Drawings represent a horizontal double cylinder engine
'constructed in the ordinary manner as to materials and general disposition,
the peculiarities of this Invention being limited to the arrangement of cylinders
and pistons and the absence of the usual valves and valve gear; various usual
external parts, such as guides, steam cock, oil cups, blow-out pipes, &c., have
been omitted in the Drawings as unnecessary to this description. The guides
indeed can very well be dispensed with entirely in small engines owing to the
length of the pistons, and in such cases it is well to make the piston rods and
stuffing boxes rather stronger than usual. The cylinders C and C¹ are cast
together; the pistons P and P¹ are represented as cast solid with the piston
rods and joined to the main shaft by connecting rods, yet they may be
constructed or.packed or connected with the shaft in any ordinary manner.
Fig. 1 is a plan of the engine, partly in section, the cutting plane passing
through the axes of the cylinders; Fig. 2 is a longitudinal vertical middle section.
of the same, the position of the cutting plane being shown at A, A, in Fig: 1;
Fig. 3 is a transverse vertical middle section, the position of the cutting plane
being shewn at B, B, in Figs. 1 and 2; similar letters in each Figure denote
corresponding parts. There are four valve ports in each cylinder; one Sat
the lower side of the first cylinder C, and one Sat the lower side of the second
cylinder C¹, both opening from the steam pipe X, one E in the first cylinder C
and one E¹ in the second cylinder C¹ opening into the exhaust pipe Y directly
opposite each other, and at an angle of ninety degrees from the steam ports
just mentioned, one L' in the first cylinder C, and one U in the second
cylinder C¹, in each case midway between the said steam and exhaust ports

page_text: communicating respectively the former L¹ with the lower or rear end of
the second cylinder C, and the latter U with the upper or forward end of the
first cylinder C, and there are also at an angle of forty-five degrees above the
said exhaust ports one port U¹ in the first cylinder C communicating with
the upper or forward end of the second cylinder C, and one L in the second
cylinder C¹ communicating with the lower or rear end of the first cylinder C.
The piston passages a, b, c, d, in the first piston P and those a, b, c, d, in
the second piston P¹ are so formed as to open communications at the proper
times as follows:-(The passage called c is not shewn on the Drawing, but
exactly corresponds to that marked c¹ in the other piston.) From the steam
ports S and S¹ the steam may be conveyed through the passage marked a to the
port marked U¹ and through the passage called c to the port marked L¹, and
also through the passage marked a¹ to the port marked L, and through the
passage marked c¹ to the port marked U; after being used it may be educted: to
the exhaust ports E and E¹ through the passages marked b and d from the
ports marked L¹ and U¹ respectively, and through the passages marked b¹
and d from the ports marked U and L respectively. In the position drawn
supposing steam to be introduced through the steam pipe X it enters at the
ports marked S and S¹, passing through the passages marked a and c¹ respec-
tively to the ports marked U¹ and U, each communicating with the upper end of
the other cylinder so that both pistons are on the "down" stroke. The exhaust
steam from the lower chambers is at the same time passing into the exhaust
pipe Y, through the ports marked E and E¹, coming through the passages
marked b and d¹ respectively from the ports marked L' and L. The valve
ports in the engine of which a drawing is given are placed in the same
transverse plane equidistant from the upper and lower ends of the cylinder;
I prefer this disposition although it is not essential. In no case however
should any two valve ports lie in the same axial line, as such an arrangement
would render necessary an immense increase in the lengths of both cylinders
and pistons; they are also shown as shorter than the piston passages; this point
is also non-essential. The number of valve ports may be increased at discretion
whether to secure a more perfect.equilibrium of steam pressure or for other
purposes. A perfect equilibrium can be obtained either by exact reduplication
of the valve ports, placing in each cylinder one steam port opposite another, one
exhaust port opposite another, &c., or by additional or auxiliary ports or
passages in the pistons, or by a combination more or less complete of both
these methods.
According to one mode of construction the position of the passages through

page_text: or around the pistons depends partially on the following considerations:-
During the stroke a portion of the surface of the piston comes opposite each
valve port, equal in length to the length of the port added to the length of
the stroke; of this space on said surface a central portion, equal in length to
the length of the port, must at all events if the port be one of those leading.
to the other cylinder be reserved solid to close the port, as herein-before set
forth. when the piston is at mid stroke in point of time, the remainder both
above and below said reserved central portion forming the mouths or openings
of two of the passages through or around the piston; the sum of the lengths
of these mouths will therefore be equal to the length of the stroke. If the
piston rod be connected with the crank by a slot in the cross head, as is
sometimes the case, these two mouths must be equal in length, and each there-
fore half the length of the stroke; but when a connecting rod is used they
must be unequal, an arrangement made necessary by the fact that the piston
in that case moves faster while in the lower half of the cylinder. To produce
accuracy therefore in the coincidence between the closing of the valve ports
and the change of stroke of the other piston the mouths of the piston passages
nearest the piston rod must be somewhat longer than half the length of the
stroke, and the others correspondingly shorter. The exact length of the
former may be determined by the following rule:-From the sum of the lengths
of connecting rod and crank subtract the square root of the difference of their
squares. The outline and position of the ends of the piston passages being
determined by these considerations the passages themselves may be formed
through or around the piston in any convenient course.
It is not essential to my Invention that the length of stroke should be the
same in each piston. For reversing as herein-before indicated I sometimes
add externally a steam chest with slide valve or four-way cock of any usual
description by which the functions of the steam and exhaust ports may be
interchanged at pleasure, making the pipe described as a steam pipe act as
an exhaust pipe, and vice versa.
Engines according to this Invention may be constructed according to any
of the various models now in use, whether stationary, portable, or locomotive,
including condensing and trunk engines, and excluding oscillating engines.
By attaching a registering apparatus of ordinary construction this engine
when worked by water or other liquid is sometimes used as a meter. In
using it as a pump the power is applied to the shaft, and one or other of the
pipes herein-before spoken of as steam and exhaust pipes is employed as a
suction pipe.
Having now set forth the nature of my Invention of "Improvements in

page_text: the: Construction of Motive-power Engines and Pumps," and explained the.
manner of carrying the same into effect, I wish it to be understood that under
the above in part recited Letters Patent I claim as of my Invention a motive-.
power engine and pump composed of two closed cylinders with double-acting
pistons so arranged that each piston acts as a four-way or double distribution
valve for the other cylinder substantially as described.
In witness whereof, I, the said Emory McClintock, have hereunto set
my hand and seal, the Twenty-eighth day of November, in the year.
of our Lord One thousand eight hundred and sixty-seven.
EMORY MCCLINTOCK. (L.s.).