AN IMPROVED STEAM ENGINE ON THE ROTARY PRINCIPLES
Year: 1833

page_text: STEIN, of Edinburgh, Esquire, send greeting.
WHEREAS His present most Excellent Majesty King William the Fourth,
by His Letters Patent under the Great Seal of Great Britain, bearing date at
Westminster, the Seventh day of May, in the third year of His reign, did,
for Himself, His heirs and successors, give and grant unto me, the said Robert
Stein, His especial licence, that I, the said Robert Stein, my exors, adñiors,
and assigns, or such others as I, the said Robert Stein, 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, my Invention of "AN IMPROVED STEAM ENGINE ON
THE ROTARY PRINCIPLES;" in which said Letters Patent is contained a proviso
obliging me, the said Robert Stein, by an instrument in writing under my
hand and seal, particularly to describe and ascertain the nature of my said
Invention, and in what manner the same is to be performed, and to cause the
same to be enrolled in His said Majesty's High Court of Chancery within six
calendar months next and immediately after the date of the said 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
Robert Stein, do hereby declare the nature of my said Invention to consist
in a hollow cylinder, having a shaft passing through its centre, with one or
more pair of pistons attached thereto in such manner as to form an ordinary.
hinge joint on the said shaft, filling up the space between it and the side of
the cylinder, and revolving freely round it, while certain bolts, let into the said
pistons for that purpose, in the progress of their revolutions within the cylinder
alternately attach the pistons to the shaft and to the cylinder in such manner

page_text: as to give, when acted upon by the steam and assisted by a fly wheel, a con-
tinuous rotary motion to the shaft without the intervention of any crank
movement. And, in further compliance with the said proviso, I, the said
Robert Stein, do hereby describe the manner in which my 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 an external side view of one of my improved engines, with one
pair of pistons only; the dotted lines represent parts within the cylinder. A is
the cylinder; B, B, the main or working shaft; C is the induction or steam
pipe and D, the eduction or escape pipe. T is part of a fly wheel; and it
may be as well here to state that similar letters are used to denote similar
parts in all the Figures. Fig. 2 is a separate view of the shaft, which has a
ratchet or toothed wheel E, cast in one piece with it or wrought upon it, as
the case may be. Figure 3 is one of the pistons colored yellow, to distinguish
it from the other, which is colored pink. F, F, are two of the parts which help
to form the hinge joint when on the shaft; G, G, is the part which acts as the
piston; and H is a mortice cut in the centre of that part to recive a bolt, the
action of which will be hereafter explained; I is a space or hollow made in
the side of the piston to admit steam between the two pistons when they come
in contact, as will also be hereafter explained. Figure 4 is the other piston
with a similar bolt mortice H, and steam space I; the part J, J, here acts as
the piston; and K, K, are the two parts which complete the hinge joint when
on the shaft; these parts K, K, it will be seen, are made to fit between the
parts F, F, on the other piston, so that when placed together, with the ratchet
or toothed wheel E, filling up the space between K, K, and the shaft B, B,
run through the whole, they will have the appearance shown at Figure 5. In
this Figure the bolts (a side view, end view, and perspective view of which are
shown at Figures 6, 7, and 8) are placed in their mortices; and this Figure
thus represents in fact the whole internal machinery of the engine, or all that
is within the cylinder. Figure 9 is a transverse section of the engine, taken
through the centre of the cylinder. A, A, is the cylinder; B, the shaft; C,
the steam pipe; D, the escape pipe; E, the ratchet wheel on the shaft;
G and J, the two pistons which I shall hereafter call the yellow and the pink
piston for the sake of distinction; m is the bolt of the yellow piston; and n is
the bolt of the pink piston; L is a nick cut in the side of the cylinder to receive
the end of the bolts. Figures 10 and 11 are similar sections, showing different
positions of the pistons in their progress round the cylinder,

page_text: Before I proceed to describe the action of the engine I will more particularly
describe the bolts m and n, which bolts, together with the mode of making
them act by means of the inclined planes at their ends, are in fact the most
important features of novelty in this Invention; these bolts lie in mortices H, H,
cut quite through the pistons as before described; and slide freely in those
mortices; one end of each bolt is cut to correspond with the nicks in the
ratchet wheel E, and the other to correspond with the nick at L, cut in the
side of the cylinder; and it will be observed that the bolts being somewhat
deeper than the mortices, the pistons with the bolts in them can only be placed
in the cylinder wheh the outer end of one bolt is in the nick at L, and the
inner end of the other bolt in one of the nicks in the ratchet wheel E, or when
the ends of both bolts are in the nicks of the ratchet wheel; and thus, in
Figure 9, it will be observed that the outer end of the bolt m is in the nick in
the cylinder at L, while the inner end of the bolt n is in the nick of the ratchet
wheel at r.
i
Having now described the various parts of my said engine, I will proceed
to describe its action, and the mode of setting it to work. The pistons G
and J being in the position shown at Figure 9, let steam be admitted through
the steam pipe C, the yellow piston G will resist the action of the steam
by means of the bolt m being shot into the nick at L in the side of the
cylinder, and the pink piston J will be driven round the cylinder, carrying
the shaft B and ratchet wheel E, with it, by means of the bolt n being
shot into the nick at r in the ratchet wheel, and thus this pink piston J will
drive the air in the cylinder before it out at the escape pipe D, until it
arrives close at the back of the yellow piston G, as shown at Figure 10.
Just at this point the outer end of the pink piston J will stop the opening
into the escape pipe D, and the steam pressing with equal force at P and Q,
both pistons would of course remain stationary, but here the impetus of the
fly-wheel, which should be on the shaft B, lends its aid, and the part S of
the ratchet wheel E, acting upon the inner end of the bolt n, the fly-wheel
carries both the pistons round till they come into the position shewn at
Figure 11. But to return to Figure 10, the action given by the fly-wheel
causes the part t of the cylinder to push the bolt m of the yellow piston
into the nick at r on the ratchet wheel E, and directly afterwards, the
moment the bolt n of the pink piston gets opposite the nick at L in the
cylinder, as shown at Figure 11, the escape passage D is again open, and
the steam rushing through the pipe C between the pistons in the space I,
checks the further progress of the pink piston J, while the parts on the
ratchet wheel E pushes the bolt n into the nick in the cylinder at L, which
now keeps the pink piston from going back, while the steam continuing

page_text: to rush in now drives the yellow piston round the cylinder in like manner
as it before drove the pink piston, carrying the shaft B and ratchet wheel E
with it till it arrives in its turn at the back of the pink piston, which is
the point where, as before described, the impetus of the fly-wheel lends its
aid, when the same action of the dent of the ratchet wheel and part t of
the cylinder on the bolts m and n, before described, again takes place, and
thus the continuous action of the engine is obtained, and what may be
used as the working shaft made to rotate without the intervention of any
crank movement.
Now, whereas it is evident that four, six, eight, or more pistons might
be introduced with advantage if the cylinder were large enough and
had corresponding nicks in its side; and whereas my said engine might
be worked by the expansive force of hot air or gas, as well as steam; but
whereas I claim as my Invention the engine herein-before described, the
pistons of which turn its main shaft by means of bolts acting in manner herein-
before described, and such my Invention being, to the best of my knowledge
and belief, entirely new, and never before used within that part of His
said Majesty's United Kingdom of Great Britain and Ireland called England,
His said Dominion of Wales, or Town of Berwick-upon-Tweed, I do hereby
declare this to be my Specification of the same, and that I do verily believe's
this my said Specification 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 my said Invention.
In witness whereof, I, the said Robert Stein, have hereunto set my s
hand and seal, this Seventh day of November, in the year of our Lord
One thousand night hundred and thirty throu