AN IMPROVED LINK MOTION FOR STEAM ENGINES
Year: 1874

page_text: LETTERS PATENT to Alexander Molville Clark, of 53, Chancery
Lane, in the County of Middlesex, Patent Agent, for the In-
vention of "AN IMPROVED LINK MOTION FOR STEAM ENGINES." -A com-
munication from abroad by John Sandall, junior, of Charlottetown,
in the. Province of Prince Edward's Island, and Dominion of
Canada.

page_text: Patent for the same, and have made solemn Declaration that it has
been communicated to me from abroad by John Sandall, junior, of
Charlottetown, in the Province of Prince Edward's Island, and Dominion
of Canada.
NOW KNOW YE, that I, the said Alexander Melville Clark, do hereby
declare that the following Complete Specification, under my hand and
scal, fully describes and ascertains the nature of the said Invention,
and in what manner the same is to be performed, in and by the following
statement, reference being had to the accompanying Sheet of Drawings,
and to the letters and figures marked thereon (that is to say) :—
This Invention relates to new and useful improvements in what is
known as the "link motion" of steam engines, adapted to locomotive,
marine, and stationary steam engines, and it consists of a link formed in
two parts, each part being connected with an eccentric, and with both
parts connected with a central eccentric, by the rod of which the two
parts are made to operate as though hinged together.
In the accompanying Drawing Figure 1 is a side view of the link,
showing its connection with the eccentric rods; Figuro 2 is a top view
of the same; Figure 3 is a view looking down from the line y, y, of
Figure 1. Similar letters of reference indicate corresponding parts.
A is the link, made in two parts B and C, but só connected with the
head D of the eccentric rod E that they act as a whole link for the
sliding valve rod box. F. G and H are the ordinary link eccentric rods,
attached to the link A in the usual manner; I and J are the eccentrics;
K is the eccentric of the rod E; L is the shaft. The inner ends of the
parts B, C, of the link have cach a cross piece M, to one of which is
attached the rod N, and to the other a tubular box O. The head D of
the rod takes hold of this tubular box. The rod N passes through the
box, consequently the eccentric moves the middle of the link A in and
out to the extent of its throw, while the other eccentrics operate upon the
ends of the link A in the usual manner. The eccentric K may be set
so as to vary this central motion of the link. The action of the valve
may consequently be varied as may be desired, but ordinarily it is set
opposite the crank, so that it answers for backing or going ahead.
Having described the nature of the Invention and the manner of per-
forming the same, I declare that what I claim as new and desire to
secitre by Letters Patent is,--

page_text: 1st. A link made of two parts, and forming a flexible whole, sub-
stantially as and for the
purposes described.
2ndly. The combination of the flexiblo link A. and the eccentric rod E,
substantially as and for the purposes described.
In witness whercof, I, the said Alexander Melville Clark, have
hercunto set my hand and seal, this Twenty-fourth day of October,
in the year of our Lord One thousand eight hundred and seventy-
four
Witness,
HY. SWALES,
53, Chancery Lane,
London.
A. M. CLARK. (L.S.)