IMPROVEMENTS IN STEAM ENGINES
Year: 1850

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, I, ALFRED
HOLL, of Greenwich, in the County of Kent, send greeting.
WHEREAS Her present most Excellent Majesty Queen Victoria, by Her
Royal Letters Patent under the Great Seal of the United Kingdom of Great
Britain and Ireland, bearing date at Westminster, the Twelfth day of August,
(One thousand eight hundred and fifty,) in the fourteenth year of Her reign,
did, for Herself, Her heirs and successors; give and grant unto me, the said
Alfred Holl, my exors, adiñiors, and assigns, Her especial license, full power,
sole privilege and authority that I, the said Alfred Holl, my exors, admiors,
and assigns, or such others as I, the said Alfred Holl, 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 "IMPROVEMENTS IN STEAM
ENGINES;" in which said Letters Patent is contained a proviso that I, the
said Alfred Holl, shall cause a particular description of the nature of my
said Invention, and in what manner the same is to be performed, by an
instrument in writing under my hand and seal, to be inrolled in Her said
Majesty's High Court of Chancery within six calendar months" next and
immediately after the date of the said in part recited Letters Patent, as in
and by the same, reference being thereunto bad, will more fully and at large
annear.

page_text: NOW KNOW YE, that in compliance with the said proviso, I, the said
Alfred Holl, do hereby declare that the nature of my said Invention, and
the manner in which the same is to be performed, are fully described and
ascertained in and by the following statement thereof, reference being had to
the Drawings hereunto annexed, and to the figures and letters marked thereon,
that is to say -
The pistons of steam engines, which work in cylinders as heretofore con-
structed, have had their circumferences packed so as to be in contact with the
cylinders for a considerable length, and therefore such rubbing surfaces of the
piston have been and are parallel to the cylinder, and in the movement of such
pistons the same parts of their circumferences have been and are constantly
in contact throughout their motion. Now, according to my Invention, the
piston is made with a curved periphery, and is caused to incline first in one
direction and then in the other, the position of the rubbing surface of the
piston constantly changing, as will readily be understood on examining the
Drawings, in the various Figures of which the same letters of reference indicate
similar parts. Figure 1 shews a longitudinal section, Fig. 2 a transverse
section, and Fig. 3, an external view, of an engine consisting of two cylin-
ders, a and b, in which two pistons, c and d, move, and it will be seen that the
periphery of each piston is curved or convex, and is in fact a portion of a
sphere; e, e, are the two piston rods fixed to the pistons c and d, their other
ends being connected directly to the crank shaft, so that in the rotation of the
shaft the pistons will, in their motion to and fro, incline first in one direction
and then in the other, which they are enabled, to do, owing to their peripheries
being curved or convex, the points of contact between the piston and the
cylinders constantly changing. The two cylinders, a and b, are connected by
a third cylinder f, in which suitable bearings are fixed for the crank, axis, or
shaft of the engines; 9 is a cover and man-hole, by which the engineer can
get at the working parts. The effect of enclosing the space between the two
cylinders, a and b, is, that that space is kept hot, whether the engines work by
condensation or by high-pressure steam, which is allowed to pass into the
atmosphere. This arrangement may, however, be dispensed with, and suitable
framing employed between the cylinders, as is shewn at Figures 4, 5, and 6,
which show three views of an arrangement of steam engines consisting of four
cylinders. And I would state that that part of my Invention which consists
of confining the space f, (which is between two cylinders by a third cylinder or
chamber, in order to keep the cylinders hot,) may be employed when ordi-
nary pistons are used, as will be understood by reference to Figures 7, 8, and.

page_text: 9, which show three views of two cylinders, a and b, with their pistons so
arranged and combined with a chamber f.
Having thus described the nature of my Invention, and the manner of per-
forming the same, I would have it understood that I do not confine myself to
the precise details, as the same may be varied without departing from my
improvements, so long as the peculiar character thereof be retained. But what
I claim are the improvements in steam engines hercin described.
In witness whereof, I, the said Alfred Holl, have hereunto set my hand
and seal, this Eleventh day of February, in the year of our Lord One
thousand eight hundred and fifty-one.