IMPROVEMENTS IN APPARATUS FOR THE CONVERSION OF RECTILINEAR INTO CIRCULAR MOTION
Year: 1852

page_text: LETTERS PATENT to Willian Baddeley, of 13, Angell Terrace,
St. Peter's, Islington, in the County of Middlesex, Engineer, for
the Invention of "IMPROVEMENTS IN APPARATUS FOR THE CONVERSION
OF RECTILINEAR INTO CIRCULAR MOTION."-A communication.
Sealed the 31st May 1853, and dated the 8th December 1852.
PROVISIONAL SPECIFICATION left by the said William Baddeley
at the Office of the Commissioners of Patents, with his Petition,
on the 8th December 1852.
I, WILLIAM BADDELEY, of No. 13, Angell Terrace, St. Peter's,
Islington, in the County of Middlesex, Engineer, do hereby declare
the nature of the said Invention for "IMPROVEMENTS IN APPARATUS FOR
THE CONVERSION OF RECTILINEAR INTO CIRCULAR MOTION" to be as follows,
viz. :—
This Invention consists in the employment of two cranks, the
first having a fixed anddeterminate radius, the second a variable
radius. The first crank is placed intermediately at any given point
upon the connecting rod. between the rectilinear motive power and
the second crank on the main shaft of the engine. The second

page_text: crank has a slot or other contrivance for enabling the end of the
connecting rod to move to and fro freely, so as that while the first
or common crank moves round in a circular orbit, the outer end of
the connecting rod is compelled to move in a circular orbit, thereby
increasing the leverage on the main crank at those points which 5
are most favourable for the transinission of motion.
SPECIFICATION in pursuance of the conditions of the Letters
Patent, filed by the said William Baddeley in the Great Seal
Patent Office on the 8th June 1853.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I,
WILLIAM BADDELEY, of No. 13, Angell Terrace, Saint Peter's Street,
Islington, in the County of Middlesex, Engineer, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Eighth day of December, in the
year of our Lord One thousand eight hundred and fifty-two, in the
sixteenth year of Her reign, did, for Herself, Her heirs and suc-
cessors, give and grant unto me, the said William Baddeley, Her
special licence that I, the said William Baddeley, my executors,
administrators, and assigns, or such others as I, the said William
Baddeley, 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 "IMPROVEMENTS IN APPARATUS FOR THE CONVERSION OF REC-
TILINEAR INTO CIRCULAR MOTION" (communicated to me by Mr. Charles
Hoppe, residing at Hamburgh, in Germany), upon the condition
(amongst others) that I, the said William Baddeley, by an instru-
ment in writing under my hand and scal, 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.

page_text: NOW KNOW YE, that this Invention consists in the employment
of two cranks, the first having a fixed and determinate radius, the
second a variable radius. The first crank is placed intermediately at
any given point upon the connecting rod between the rectilincar
motive power and the second crank on the main shaft of the engine.
The second crank has a slot, or other contrivance, for enabling the
end of the connecting rod to move to and fro freely, so as that while
the first or common crank moves round in a circular orbit, the outer
end of the connecting rod is compelled to move in an elliptical orbit,
thereby increasing its leverage on the main crank at those points
which are most favorable for the transmission of motion.
And in order that the same may be more fully understood,
reference is had to the following description thereof, and to the
Drawings hereunto annexed (that is to say):
Figure 1: a, b, represents the connecting rod of a horizontal
cylinder steam engine; A, B, the length of stroke, say eighteen
inches; C, c, is a nine inch crank, placed midway between the two
extremities of the connecting rod; upon the main shaft D, there is
an eighteen inch slotted crank E, in which a guide pin and block e,
attached to the end a, of the connecting rod a, b, traverses. In
consequence of this arrangement, the centre of the connecting
rod c, moves round in a circular orbit, f, g, h, while the extreme
end of the connecting rod a, moves round in the elliptical orbit
shown by the red dotted line i, k, l, instead of the circular orbit
shown by the black dotted lines, which it would have described, if
attached to a nine inch crank in the usual manner.
Figure 2 shews the connecting rod a, b, attached to an eighteen
inch crank F, upon the main shaft D, by means of a link M, which
travels round the main shaft, while the end of the connecting rod a,
describes the same elliptical orbit i, k, l, as in the preceding
arrangement, thus enabling the motive power to act in a more
favorable position, and through a longer space, by which means a
considerable advantage is obtained.
In both these examples the intermediate crank is shewn as
applied to the middle of the connecting rod, and in many cases this
will be an advantageous arrangement; it may, however, be placed

page_text: at any convenient point intermediate between the power and the
nain shaft. The greater the distance between the intermediate
crank and the main crank, the greater will be the range of motion
and effective length of crank, and vice versa.
What I claim as new, and constituting the Invention which has
been communicated to me, is, the conversion of rectilinear into
circular motion by the 'employment of two cranks; by the first of
which the movement of the connecting rod is controlled and guided,
and its further end compelled to move in an elliptical orbit, thereby
increasing its leverage upon the main crank at those points most
favourable.for the transmission of power.
In witness whereof, I, the said William Baddeley, have here-
unto set my hand and seal, this Eighth day of June, in the
year of our Lord One thousand eight hundred and fifty-three.
Witness,
J. T. HARSTON,
12, Cursitor Street.
WILLIAM BADDELEY. (L.S.)