IMPROVEMENTS IN STEAM AND OTHER ENGINES
Year: 1875

page_text: PROVISIONAL SPECIFICATION left by Thomas Messenger and George
Dundas Churchward at the Office of the Commissioners of Patents,
with their Petition, on the 28th July 1875
We, THOMAS MESSENGER and GEORGE DUNDAS CHURCHWARD, both
of Dover, in the County of Kent, Civil Engineers, do hereby declare the
nature of the said Invention for "IMPROVEMENTS IN STEAM AND OTHER
ENGINES," to be as follows:-
Our Invention relates to a method of connecting the reciprocating
parts, such as the pistons of steam, air, water, gas, and other engines,
and of other reciprocating machinery to their rotating parts, such as
cranks
The principle upon which our Invention is based is embodied in the
diagram, Figure 1, of the accompanying Sheet of Drawing, upon which
A indicates a globe, B, B, pins fixed to globe in its rolling axis,
C, C, balls fixed to the globe in its transverse axis and embraced by part
of a socket D, D; E, E, crank arms embracing the pins B, B, and fixed

page_text: to the shafts F, F, which are capable of simultaneous revolution;
H, I, guiding blocks capable of a reciprocating motion on the guiding
bars I, I, in a true plane with the axis of the crank shafts.
The movements involved in converting the reciprocating into the
circular motion, are as follows The crank shafts F, F, in revolving
cause the axis b, b', of the globe A by means of the pins B, B, to roll in
circles, and the transverse axis c, c', is compelled to reciprocate in the
arc of a circle, and in a true plane with the axis of the revolving
shafts F, F, by means of the guide bars I, I, then all other points
through any other transverse axis, or in other words around the
periphery of the globe, will-also reciprocate-in-arcs of circles, but not in
a true plane with the axis, for instance, the points on the globe at right
angles to the transverse axis c, c¹, will move in reciprocating in the form
of a figure of 8, as shown at K, K, and all other points around the
periphery will describe similar figures
Figures 2 and 3 show an application of our Invention to a three-
cylinder steam engine, Figure 2 being a side view showing one of the
three cylinders, and Figure 3 an end view of the three cylinders.
L, middle or guiding cylinder attached to that part of the globe which
reciprocates in a true plane with the axis of the revolving shaft F;
M, M, side cylinders attached to points N, N, on the globe corresponding
with their respective centre lines, allowance being made in their
guiding blocks for a side movement to admit of the figure of 8 motion,
or we may use connecting rods for this purpose.
We propose to utilize these movements in other manners than as
illustrated, Figures 2 and 3, for instance, a single cylinder engine may
be made, the rolling axis being coupled to the transverse or reciprocating
axis by a bell-crank lever universally jointed to a fulcrum where the
levers join, or a two-cylinder engine may be made with the bell crank
attached to one cylinder, and another lever for the other cylinder
jointed tranversely on the rolling arm of the bell-ciank lever (so that
when one engine is on its centre the other is at half stroke), this
Jointing of the second lever will compensate for the figure of 8 move-
ment.

page_text: Invention admits of a method of regulating the power. For example,
supposing the reciprocating aims attached to a number of force pumps
and a means provided for sliding the pins B, B, nearer to or further
from the centre of the crank shaft, then the stroke of all the pumps
5 would be either decreased or increased