A Double-centre'd Steam Engine:
Year: 1843

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, I, FREDERIC
LEWIS WESTENHOLZ, of No. 151, Regent Street, in the County of Middlesex,
Merchant, send greeting.
WHEREAS, in consequence of a communication from a Foreigner residing
abroad, I am in possession of an Invention of "A Double-centre'd Steam
Engine:"
And whereas Her present most Excellent Majesty Queen
Victoria, by Her Letters Patent under the Great Seal of Great Britain,
bearing date at Westminster, the Twenty-fifth day of July, in the seventh
year of Her reign, did, for Herself, Her heirs and successors, give and grant
unto me, the said Frederic Lewis Westenholz, Her especial license, that I,
the said Frederic Lewis Westenholz, my exors, adñiors, and assigns, or such
others as I, the said Frederic Lewis Westenholz, my exors, adñiors, or assigns,
should at any time agree with, and no others, from time to time and at all
times during the term of years therein expressed, should and lawfully might
make, use, exercise and vend, within England, Wales, and the Town of
Berwick-upon-Tweed, and also in the Islands of Guernsey, Jersey, Alderney,
Sark, and Man, and in all Her said Majesty's Colonies and Plantations abroad,
the said Invention of "A DOUBLE-CENTRE'D STEAM ENGINE;" in which said
Letters Patent is contained a proviso obliging me, the said Frederic Lewis
Westenholz, by an instrument in writing under my hand and seal, particularly to
describe and ascertain the nature of the said Invention, and in what manner
the same is to be performed, and to cause the same to be enrolled in Her said
Majesty's High Court of Chancery within six calendar months next and

page_text: immediately after the date of the said in part recited Letters Patent, as in
and by the same, reference being thereunto had, will more fully and at large
appear.
NOW KNOW YE, that in compliance with the said proviso, I, the said
Frederic Lewis Westenholz, do hereby declare the nature of the said Inven-
tion to consist in a steam engine revolving on two centres excentric to
each other, one centre being the revolving axis of a wheel which may be called
a fly wheel, and the other the fixed axis of a double cylinder, the piston rods of
which are connected by a cross head; which cross head is attached to one of
the spokes or a given point of the fly wheel by a fixed pin, round which the
cross head turns, and thus drives round the fly wheel and its axis, which axis
thus becomes a driving shaft. And in further compliance with the said proviso,
I, the said Frederick Lewis Westenholz, do hereby describe the manner in
which the said Invention is to be performed by the following statement thereof,
reference being had to the Drawing annexed, and to the figures and letters
marked thereon, that is to say :-
DESCRIPTION OF THE DRAWING.
Figure 1 is a side elevation of the engine; Figure 2 is a sectional plan of
same; and Figure 3 is a vertical section taken transversely through the
cylinders; and similar letters are used to denote similar parts in all the Figures.
A, A, is the foundation or bed plate, upon which is fixed the framing containing
the steam passages and the bearing for the centre or axis, upon which the
cylinders revolve; also the standards for supporting the centre or shaft of the
fly wheel and driving pulley; these two centres being the peculiarity of con-
struction which induced me to style the Invention "A Double-centre'd Steam
Engine." B is a steam pipe leading from a boiler, and is fixed to the top of
the steam chest C, which chest is screwed to the bed plate A. Within this
chest is what I call a slide or regulator D, seen best in Figure 3, which is for
the purpose of admiting to or shutting off the steam from the cylinders, and
also for reversing the engine. It is worked by the lever handle E, as occasion
may require. F, F, are two hollow columns forming steam passages, which
are also fixed to the bed plate, and they support at top a cast iron entablature
in which all the steam passages G, G³, Figure 2, leading to the cylinders, and
having between them a boss H, which carries the axis I upon which the
cylinders J, J', revolve. This axis is accurately fitted in the boss, and is
prevented from turning by a key r; the cylinders have also cast between them
passages K, K', leading to the ports of the cylinders, the centre portion L
having a recess to receive the brasses M, M, which are bored out to receive the

page_text: axis I, and which I will allude to hereafter. N, N', are two circular plates
serving the purpose of a slide valve, which are accurately ground and fitted to
each other. Each of these plates have two openings n, n', in them placed
opposite each other; and each opening extends one fourth the circle or an
are 90°; they are shown separately in Figure 4; and as the cylinders revolve one
of the openings will be admitting steam thereto during one fourth part of their
revolution, while the other will be open to what will then be the exhausting
passage. The plate N is screwed to the boss H, and remains stationary; the
other plate N' is fixed to the casting L between the two cylinders and revolves
with them. O is a stuffing box placed outside the circular slides to prevent
the escape of the steam; and there is also packing p introduced on each side
around the axis to prevent the steam escaping in this direction. The axis I in
this engine remains stationary, the cylinders and all the parts fixed thereto
revolving upon it. In order to adjust the pressure between the rubbing
surfaces of the two circular slides, and to prevent too much friction, the
axis I is made to slide longitudinally, and at one end passes through a strong
spring P, which is provided with screw nuts to draw the two faces of the
circular slides together (the spring having sufficient elasticity to enable the
slides to revolve, rubbing against each other easily without allowing the steam
to escape between them). M, M, are the two brasses before alluded to; they
are of a peculiar construction and they form (when placed together) a bearing
to support the cylinders upon the axis I, and are so contrived that they can be
tightened up to it should any wear take place, as shown in Figures 5 and 6
hereafter explained. A square hole is formed in the solid part between the
two cylinders, two sides being bevilled as seen in Figure 2, and two parallel,
as in Figure 3; and as the brasses are brought inwards, they act as wedges by
the bevilled sides of the hole, and thus bear tightly upon the axis. At the
outer end of the brasses is placed a plate S, having adjusting screws T, T,
tapped into it. The heads of these screws pass through a circular plate U, which
plate is fixed to the cylinders by screws u, u, seen in Figures 3 and 6, and the
screws have collars t, t, so that as the heads are turned the shoulders will bear
against the plate U, and thereby force the plate S along the thread of the
screw against the ends of the brasses M, M, and force them inwards like a
wedge upon the axis I, and thus keep it tight in its bearing. These brasses
are shown of large size at Figures 5 and 6. At the end of the axis I is a
nut V, with a washer bearing against the plate U, which forms an abutment
to the draft of the spring and nut. At its other end W, is an oil cup screwed
to the cylinders for the purpose of lubricating the axis I and the other working
parts of the engine. Within the cylinders are two ordinary pistons, to which are

page_text: attached the piston rods a, a', which are fixed to a cross head b, through which
is a pin c, passing through a hole and connected to one of the arms of the fly
wheel d. This fly wheel is connected to a shaft e, which forms its centre or
axis, and which turns in bearings on the standards f, f, which bearings are
screwed to the bed plate A, and upon the shaft e is a driving pulley g, for the
purpose of communicating power to other machinery when necessary. Be-
neath the bed plate is fastened a chest or box h, which forms a communication
between the steam chest and the passages in the columns F and F. x, x,
are two cocks for blowing off the condensed water from the cylinders and
passages when starting the engine. The engine as represented in the accom-
panying Drawing is proceeding in the direction indicated by the arrow on the
fly wheel in Figure 1, the steam forcing the pistons outwards, which will have
attained their full outward stroke as soon as the pin in the cross head has
reached its vertical position immediately over the centre of the axis I of the
cylinder, as indicated at Q, and their full inward stroke as soon as the pin
arrives at its lowest point below the centre of the said axis. Figure 5 repre-
sents a section of a portion of the casting L, showing the recess bevelled on
two sides for receiving the brasses M, M; and Figure 6 is a similar section
taking at right angles with the former, showing the two parallel sides of the
said recess, and Figure 7 is an end view of Figures 5 and 6, the brass ring U
being removed. Figure 8 is an end view of the nut V, with the oil box W
removed.
Having now described the various parts of the engine in detail, I will pro-
ceed to describe its action. In the position in which the lever handle E is
placed in Figure 1, steam is passing from the steam chest C, through the left
hand passage 1 of the box h, through the column F, and passages G, K, to the
back of the pistons in the cylinders J, J'; the steam which was in front of
the pistons escaping from the cylinder ports into the passages K', G', down the
column F, and through the passage 2 of the box h, to the right hand passage 3
of the steam chest C, passing into the interior of the regulator D in its
progress, and finally into the central eduction passage i. The openings in the
circular slides N, N', if made as shown in Figure 4, allow the steam to be
admitted with the full pressure during the fourth part of the stroke of the
piston. It is then cut off for one other quarter of the stroke by the plain or
solid part of the slide N' coming against and covering the opening of the
slide N, it being borne in mind that one slide is always stationary. By this
time the pistons will have arrived at the full forward stroke, and the opposite
opening in the slide N¹ now coming against the opening in the slide N, the
steam will flow through the other opening and act against the front of the pistons

page_text: for a quarter of the stroke, and be cut off as before by the next solid part of the
slide N', thus producing the backward stroke of the pistons; and during this
last operation the steam behind the pistons will be escaping through the
eduction passages, as before described. Thus the openings in the slide N¹
alternately as it revolves forms the induction and eduction passages for the
steam. In order to reverse the engine it is only necessary to move the regu-
lator D, by turning the lever handle E in the opposite direction to which
it is shewn in Figure 1. This will open a communication for the passage
of the steam to the column F and passages G, K', when those passages, which
before were the induction passages, as far as the regulator N, will become
the exhausting passages, both being made communicative with the central
eduction pipe i, by means of the regulator D. When the lever handle E
is placed in a vertical position the engine will be stopped, as the regulator
will then cover all the passages in the steam chest. It is scarcely necessary
to state that the inward and outward action of the cross head turning on
the pin C, with reference to the double centre of revolution, namely, the
centre of the cylinders at I, and the centre of the fly wheel at e, will, being
excentric to each other, necessarily cause the prolonged axis or driving
shaft to revolve together, with any pinions, drums, or pulleys and bands,
that may be attached thereto for the purpose of communicating motion to
machinery.
Now, whereas it is evident one cylinder may be used instead of two, and that
the pin over and round which the cross head of the piston rods works may be
on any suitable given point of that wheel which I have called a fly wheel,
dependent only on the length of the stroke of the piston; and whereas there
may be various ways of arranging the steam passages and the admission and
emission of the steam to the cylinder, and also tightening up of the two
rubbing surfaces of the circular slides; but whereas I claim as the Invention
aforesaid a double centred steam engine as aforesaid, having its steam cylinder
or cylinders mounted on an axis excentric to the axis of the wheel which I
have called a fly wheel, and which fly wheel is driven round by being
connected with the head of the piston rod of the cylinder as herein-before
described; and such Invention being, to the best of my knowledge and
belief, entirely new, and never before used within that part of Her said
Majesty's United Kingdom of Great Britain and Ireland called England, Her
said Dominion of Wales, and Town of Berwick-upon-Tweed, nor in the Islands
of Guernsey, Jersey, Alderney, Sark, and Man, nor in any of Her said
Majesty's Colonies or Plantations abroad, I do hereby declare this to be my
Specification of the same, and that I do verily believe this my said Speci-

page_text: fication doth comply in all respects, fully and without reserve or disguise, with
the proviso in the said herein-before in part recited Letters Patent contained;
wherefore I hereby claim to maintain exclusive right and privilege to the
said Invention.
In witness whereof, I, the said Frederic Lewis Westenholz, have here-
unto set my hand and seal, this Third day of August, in the
our Lord One thousand eight hundred and forty-three.
year of