IMPROVEMENTS IN MACHINERY FOR OBTAINING MOTIVE POWER, PARTS OF WHICH IMPROVEMENTS ARE ALSO APPLICABLE FOR OTHER PURPOSES." PROVISIONAL SPECIFICATION
Year: 1868

page_text: LETTERS PATENT to Henry John Behrens and Edward Dart, of
2, Rue Ste. Appoline, Paris (Empire of France), Gentlemen, for
the Invention of "IMPROVEMENTS IN MACHINERY FOR OBTAINING MOTIVE
POWER, PARTS OF WHICH IMPROVEMENTS ARE ALSO APPLICABLE FOR OTHER
PURPOSES."
PROVISIONAL SPECIFICATION left by the said Henry John Behrens
and Edward Dart at the Office of the Commissioners of Patents,
with their Petition, on the 17th August 1868.
We, HENRY JOHN BEHRENS and EDWARD DART, of 2, Rue Ste.
Appoline, Paris (Empire of France), Gentlemen, do hereby declare the
nature of the said. Invention for "IMPROVEMENTS IN MACHINERY FOR
OBTAINING MOTIVE POWER, PARTS OF WHICH IMPROVEMENTS ARE ALSO APPLICABLE
FOR OTHER PURPOSES," to be as follows:-
The machine forming the subject of the improvements hereafter
described is particularly intended to be used as a motive-power engine,
it may be driven by steam, water, or any other fluid or liquid, the same
principle may however be applied to the construction of pumps to

page_text: which driving power must be applied. Its working parts, the combi-
nation of which form the essential features of the machine, are two
pistons mounted on two parallel shafts, geared together so as to revolve
in contrary directions, and at the same speed. These pistons, segmental
in form, revolve in two annular spaces in communication with one
another, and the shafts are placed at such a distance that the naves
forming the centre of the said spaces are indented in such manner as to
allow passage to the other piston, which being adjusted prevents steam,
When the
water, or other fluid from passing between it and the nave.
machine is arranged to work as a motive-power engine with steam it
acts alternately on each piston by acting on the circumference of the
other, which is then drawn by the gearing, and their motion thus
rendered uniform, and when the same principle is applied to a pump
the vacuum is made by the displacement of each piston, which at the
same time that it allows a quantity of water to enter by one opening,
causes a similar quantity to pass off or escape by another.
A motive-power engine constructed on this principle, although giving
good results, would not realize a sufficient utilization of the steam to be
economical. With the view however of obtaining this advantage we
have applied to those machines the principle of utilizing the expansion
of the steam known by the name of the Woolf system, which being
applied to some machines with pistons having a rectilinear motion have
always given excellent results. For this purpose we employ in pairs the
arrangement that we have just described, that is to say, two cylinders
of the same diameter, but one three or four times longer than the other.
We place these two cylinders by the side of one another on the same
shafts, and the eduction orifice of the smaller corresponding with the
inlet orifice of the larger by means of a suitable steam pipe, so that the
steam after having acted at full pressure in the small cylinder then
passes into the larger, and acts on the larger surfaces by expansion. In
this manner we utilise the expansive force in the most simple manner
without employing separate valves worked by cams or eccentrics, which
always entail a loss of power.
The accompanying Drawing is a view of a machine with our improve-
ments applied thereto.
Figure 1 is an end view; Figure 2 is a vertical and longitudinal
section taken through the line E, F, of Figure 1; Figure 3 is a transverse
section taken through the line A, B, of Figure 2; Figure 4 is another

page_text: transverse section taken through the line C, D, of Figure 2; Figure 5 is a
horizontal section taken through the line G, H, of Figure 1; Figure 6 is
an end view with two partial sections taken through the lines I, J, and
J, K,, of Figure 7, to show the communication of the slide valves for the
inlet and exit of steam; Figure 7 is another horizontal section, taken.
through the line G, H, of Figure 6.
S is the small cylinder composed of two cylindrical spaces m and m',
in communication with one another, and in which the pistons p and p'
rotate, which are adjusted in each of the spaces, and fixed on their
respective shafts e, e', by the discs q, q'. These two spaces each contain
one of the naves or cylindrical washers n and n', which are indented or
have a portion of each of their circumferences cut away to allow the
pistons to pass, and to prevent steam or other fluid from passing when
the said pistons come in contact with the parts of the naves n and' n',
that are cut away concentric with the shafts e, e', which gear together
by means of the wheels f and f'. R is the lid of the cylinder with
cavities, in which the discs q and g of the pistons are carefully adjusted.
The ends of the shafts e, e', pass through the lid through a stuffing box T','
carrying at the end a pulley or fly wheel X, or the lid may simply act as
a support as at U, Figure 2. The lid is firmly secured to the body of
the cylinder, which with the two washers or naves, two pistons, two
shafts, and two toothed wheels, compose the fundamental principle
(essence) of our Invention, but as we have before stated we believe that
we have added to this simple principle, in which the pressure of the steam
alone would be utilised, an arrangement enabling us to take advantage
of the expansive force or the expansion of the steam, and thus insuring
for our machines a result much more considerable. To accomplish this
the casing of the cylinder S is prolonged sufficiently far to form a sort
of chamber in which the wheels f and f' are enclosed, and to receive
the body of another machine composed as the other with a cylinder or
envelope L, with two annular spaces M, M'; two naves or washers N, N',
two pistons P, P', with their respective discs Q, Q, fixed on the prolon-
gation of the shafts e and e', a cover R', with a stuffing box T, and a
cavity U' forming a support, the construction of the latter being entirely
similar to the first before described, with this difference that the pistons
are three times wider, all being of the same diameter, whereby a surface:
three times more extensive is presented to the action of the steam. The
inlet orifice for the, steam d (Figures 4 and 5 of this large cylinder cor

page_text: ,
responds with the outlet orifice 'c (Figures 3 and 5) of the small cylinder
by means of a passage wo (Figures 2 and 5) passing behind the small
cylinder S. The two cylinders are furnished with projecting flanges v, v',
whereby the whole is united to a base plate or foundation W, W'. In
order to have the steam supply pipe and the eduction pipe on a level with
the cylinders the small cylinder has one inlet passage a (Figure 3),
turning externally around it at a height with the suitable opening, and
the large cylinder has a similar eduction z, Figure 4, to take the steam
to the upper part, from whence it may pass to the atmosphere, or be
conveyed into a condenser.
The action of the machine is therefore as follows:-Steam brought
from the boiler enters into the passage a, and passes by the aperture b
into the cylinder S, where it acts at full pressure, first, on one of the
pistons p, p', which then sets the other in motion, and afterwards on the
other, which in this case equally gives motion to the first by means of
wheels fand f'. The steam then acts alternately on each of the pistons
in the direction of the arrows, taking as its guide (point d'appui) the
circumference of the other, and as is afterwards driven through the aper-
ture c, where the passage w takes it to the inlet orifice d of the large
cylinder, in which it acts on the pistons P, P', in the same manner by
expansion, and escapes by the passage z.
In order to obtain all the useful power of the steam issuing from the
small cylinder on the pistons of the large it is necessary that the rela-
tive position of the pistons on their shafts are as shown in the Drawing,
that is to say, that when the smaller piston is on the point of allowing
the steam to escape the larger piston P' must have just closed its inlet
orifice d in order that all the steam coming from the piston p may exert
its expansive power directly against the face of the piston P, and vice
verså.
After what has preceded it will be understood that the relation between
the length of the small and large piston may be fixed at will according
to the degree of expansion desired to be obtained. It is also evident that
the toothed wheels need not be enclosed in a sort of chamber between the
two cylinders, which could be back to back and even cast in one piece, and
that the two shafts can be placed in all positions without changing the
action of the machine, the arrangement of the details of which may be
varied as desired. The body of the cylinders may be surrounded with
an envelope to preserve the changes of temperature. Instead of there

page_text: being a piston on each shaft there might be two diametically opposed, on
which the steam would act alternately for a quarter of a revolution;
this arrangement would have the advantage of balancing the weight of
the pistons.
For certain purposes where it is necessary the motion of the machine
should be reversed it is necessary to cut off the passage of the steam in
the passage w by means of slide valves or other equivalent arrangements
in order to establish suitable communications with the inlet and outlet
orifices.
Figures 6 and 7, show an arrangement whereby this end may be
effected.
t
At the top of the apertures of the different steam passages there are
placed on each side of the cylinders the valves g and g', sliding in the
boxes h and h', screwed to the lateral faces of the cylinders. The rods
of the valves i, i, are united to a lever s, jointed at a fixed point 1,
and provided at one end with a handle y. The steam has access into
the valve boxes h and h' by a passage coming from the upper part of
the cylinder, and the escape orifices o, o', lead into a common pipe O, the
opening in which being also placed at the upper part of the cylinders
may be provided with an escape pipe. In the position indicated in the
Drawing the steam following the direction of the arrows enters by the
pipe into the valve box h, thence into the small cylinder by the orifice b
(all the other orifices being closed by the valve g'), acts on the pistons,
then escapes at c into the pipe w, to enter at d into the large cylinder,
thence to escape by the aperture o in the exit pipe o. By placing the
lever in the position indicated by the dotted lines Y, Y', the position of
the valves will be changed, and the steam entering the opposite orifices
occasions the change in the direction of the motion of the machine to
take place.
30 SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Henry John Behrens and Edward Dart in the
Great Seal Patent Office on the 17th February 1869.
TO ALL TO WHOM THESE PRESENTS SHALL COME, we, HENRY
JOHN BEHRENS and EDWARD DART, of 2, Rue Ste. Appoline, Paris
35 (Empire of France), Gentlemen, send greeting.

page_text: WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Seventeenth day of August, in the year
of our Lord One thousand eight hundred and sixty-eight, in the thirty-
second year of Her reign, did, for Herself, Her heirs and successors,
give and grant unto us, the said Henry John Behrens and Edward
Dart, Her special licence that we, the said Henry John Behrens and
Edward Dart, our executors, administrators, and assigns, or such others
as we, the said Henry John Behrens and Edward Dart, our 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 MACHINERY
FOR OBTAINING MOTIVE POWER, PARTS OF WHICH IMPROVEMENTS ARE ALSO
APPLICABLE FOR OTHER PURPOSES," upon the condition (amongst others) that
we, the said Henry John Behrens and Edward Dart, our executors or
administrators, by an instrument in writing under our, or their, or
one of their hands and seals, should particularly describe and ascer-
tain the nature of the said Invention, and in what manner the samo
was to be performed, and cause the same to be filed in the Great Scal
Patent Office within six calendar months next and immediately after the
date of the said Letters Patent.
NOW KNOW YE, that we, the said Henry John Behrens and Edward
Dart, do hereby declare the nature of the said Invention, and in what
manner the same is to be performed, to be particularly described and
ascertained in and by the following statement, reference being had to
the Drawings hereunto annexed, and to the letters and figures marked
thereon, that is to say :-
The machine forming the subject of the improvements hereafter
described is particularly intended to be used as a motive-power engine,
it may be driven by steam, water, or any other fluid or liquid; similar
improvements may however be applied to the construction of pumps to
which driving power must be applied. Its working parts, the combina-
tion of which form the essential features of the machine, are two pistons
mounted on two parallel shafts geared together so as to revolve in
contrary directions and at the same speed. These pistons, segmental in
form, revolve in two annular spaces in communication with one another
and the shafts are placed at such a distance that the naves forming

page_text: the centre of the said spaces are indented in such manner as to allow
passage to the other piston, which being adjusted prevents steam, water,
or other fluid from passing between it and the nave. When the machine
is arranged to work as a motive-power engine with steam it acts
alternately on each piston by acting on the circumference of the other,
which is then drawn by the gearing and their motion thus rendered
uniform, and when the same principle is applied to a pump the vacuum
is made by the displacement of each piston, which at the same time
that it allows a quantity of water to enter by one opening causes a
similar quantity to pass off or escape by another.
A motive-power engine constructed on this principle, although giving
good results, would not realize a sufficient utilization of the steam to be
economical. With the view, however, of obtaining this advantage we
have applied to those machines the principle of utilizing the expansion
of the steam known by the name of the "Woolf" system, which being
applied to some machines with pistons having a rectilinear motion have
always given excellent results. For this purpose we employ in pairs
the arrangement that we have just described, that is to say, two
cylinders of the same diameter, but one three or four times longer
than the other. We place these two cylinders by the side of one
another on the same shafts, and the eduction orifice of the smaller
corresponding with the inlet orifice of the larger by means of a suitable
steam pipe, so that the steam after having acted at full pressure in
the small cylinder then passes into the larger and acts on the largest
surfaces by expansion. In this manner we utilize the expansive force
in the most simple manner without employing separate valves worked
by cams or eccentrics, which always entail a loss of power.
The accompanying Drawing is a view of a machine with our improve-
ments applied thereto.
Figure 1 is an end view; Figure 2 is a vertical and longitudinal
section taken through the line E, F, of Figure 1; Figure 3 is a transverse
section taken through the line A, B, of Figure 2; Figure 4 is another
transverse section taken through the line C, D, of Figure 2; Figure 5 is
a horizontal section taken through the line G, H, of Figure 1; Figure 6
is an end view with two partial sections, taken through the lines I, J,
and J, K, of Figure 7 to show the communication of the slide valves
for the inlet and exit of steam; Figure 7 is another horizontal section,
taken through the line G, H, of Figure 6.

page_text: S is the small cylinder composed of two cylindrical spaces m and m'
in communication with one another, and in which the pistons p and p'
rotate, which are adjusted in each of the spaces and fixed on their
respective shafts e, e', by the discs q, q'; these two spaces each contain
one of the naves or cylindrical washers n and n', which are indented or
have a portion of each of their circumferences cut away to allow the
pistons to pass and to prevent steam or other fluid from passing when
the same pistons come in contact with the part of the naves n and n'
that are cut away concentric with the shafts e, e', which gear together
by means of the wheels f and f'. R is the lid of the cylinder
with cavities in which the discs q and q' of the pistons are carefully
adjusted. The ends of the shafts e, e¹, pass through the lid through
a stuffing box T carrying at the end a pulley or fly wheel X, or the
lid may simply act as a support as at U, Figure 2. The lid is firmly
secured to the body of the cylinder with which the two washers or
naves, two pistons, two shafts, and two toothed wheels compose the
fundamental principle (essence) of our Invention, but as we have before
stated we believe that we have added to this simple principle, in which
the pressure of the steam alone would be utilized, an arrangement
enabling us to take advantage of the expansive force or the expansion of
the steam and thus insuring for our machines a result much more con-
siderable. To accomplish this the casing of the cylinder S is prolonged
sufficiently far to form a sort of chamber in which the wheels f and f'
are enclosed, and to receive the body of another machine composed as
the other with a cylinder or envelope L with two annular spaces M, M',
two naves or washers N, N', two pistons P, P', with their respective
discs Q, Q', fixed on the prolongation of the shafts e and e'; a cover R
with a stuffing box T' and a cavity U' forming a support, the construction
of the latter being entirely similar to the first before-described with this
difference that the pistons are three times wider, all being of the same
diameter, whereby a surface three times more extensive is presented to
the action of the steam. The inlet orifice for the steam d (Figures 4
and 5) of this large cylinder corresponds with the outlet orifice c
(Figures 3 and 5) of the small cylinder by means of a passage 10
(Figures 2 and 5), passing behind the small cylinder S. The two
cylinders are furnished with projecting flanges v, v', whereby the whole
is united to a base plate or foundation W, W'. In order to have the
steam supply pipe and the eduction pipe on a level with the cylinders
the small cylinder has one inlet passage a (Figure 3) turning externally

page_text: around it at a height with a suitable opening, and the large cylinder has
a similar eduction z, Figure 4, to take the steam to the upper part, from
whence it may pass to the atmosphere or be conveyed into a condenser.
The action of the machine is therefore as follows:-Steam brought
from the boiler enters into the passage a and passes by the aperture 6
into the cylinder S, where it acts at full pressure, first on one of the
pistons p, p', which then sets the other in motion, and afterwards on the
other, which in this case equally gives motion to the first by means of
wheels fand f. The steam then acts alternately on each of the pistons
in the direction of the arrows, taking as its guide (point of support) the
circumference of the other, and as is afterwards driven through the
aperture c, where the passage to takes it to the inlet orifice d of the
large cylinder, in which it acts on the pistons P, P', in the same manner
by expansion and escapes by the passage z.
In order to obtain all the useful power of the steam issuing from the
small cylinder on the pistons of the large it is necessary that the relative
position of the pistons on their shafts are as shown in the Drawing, that
is to say, that when the smaller piston is on the point of allowing the
steam to escape the larger piston P' must have just closed its inlet
orifice d in order that all the steam coming from the piston p may
exert its expansive power directly against the face of the piston P, and
vice versa.
After what has preceded it will be understood that the relation
between the length of the small and large piston may be fixed at will
according to the degree of expansion desired to be obtained. It is also
evident that the toothed wheels need not be enclosed in a sort of
chamber between the two cylinders, which could be back to back, and
even cast in one piece, and that the two shafts can be placed in all
positions without changing the action of the machine, the arrangement
of the details of which may be varied as desired. The body of the
cylinders may be surrounded with an envelope to preserve the changes
of temperature. Instead of there being a piston on each shaft there
might be two diametrically opposed, on which the steam would act
alternately for a quarter of a revolution; this arrangement would have
the advantage of balancing the weight of the pistons.
For certain purposes where it is necessary the motion of the machine
should be reversed it is necessary to cut off the passage of the steam in
the passage w, and which is accomplished by means of slide valves or

page_text: other equivalent arrangements in order to establish suitable communica-
tions with the inlet and outlet orifices.
Figures 6 and 7 show an arrangement whereby this end may be
effected. At the top of the apertures of the different steam passages
there are placed on each side of the cylinders the valves g and g'
sliding in the boxes hand h' screwed to the lateral faces of the cylinders,
the rods of the valves i, i, are united to a lever s jointed at a fixed
point and provided at one end with a handle y. The steam has access
into the valve boxes h and ' by a passage t coming from the upper part
of the cylinder, and the escape orifices o, o', lead into a common pipe O,
the opening in which being also placed at the upper part of the cylinders
may be provided with an escape pipe. In the position indicated in the
Drawing the steam following the direction of the arrows enters by
the pipe into the valve box h, thence into the small cylinder by the
orifice (all the other orifices being closed by the valve g') acts on
the pistons, then escapes at c into the pipe w to enter at d into the large
cylinder, thence to escape by the aperture o in the exit pipe O. By
placing the lever in the position indicated by the dotted lines the position
of the valves will be changed and the steam entering the opposite
orifices occasions the change in the direction of the motion of the
machine to take place.
And having now described the nature of our said Invention, and
in what manner the same is to be performed, we declare that we claim
as our improvements in machinery for obtaining motive power, parts
of which improvements are also applicable for other purposes,―
First. The employment of pistons acting in pairs in annular spaces
communicating with one another and capable of being subjected to the
action of any power whatever to transmit motion to shafts to which they
are fixed, substantially as herein-before described.
Second. The employment of fixed naves having a portion cut out in
their circumference to form a junction with the external surface of the
pistons, and to prevent the passage of steam or other fluid, substantially
as described.
Third. The application of a system, known as "Woolf's," to rotary
machines by adding to a first machine a second of greater dimensions,
the steam issuing from the first passing into the other by its power of
expansion, substantially in manner herein-before described.

page_text: Fourth. The employment of pistons placed in the relative positions
herein-before named to obtain the greatest useful effect of the steam
coming from the boiler, substantially as described.
Fifth. The arrangement of the steam passages in combination with
those of the slide valves to obtain the change of motion in the machine,
all substantially as herein-before described.
In witness whereof, we, the said Henry John Behrens and Edward
Dart, have hereunto set our hands and seals, this Thirteenth day
of February, in the year of our Lord One thousand eight hundred
and sixty-nine.
HENRY JOHN BEHRENS. (L.S.)
EDWARD DART.
(L.S.)