Improvements in Linkages for Transmitting Motion.
Year: 1890

page_text: Date of Application, 22nd May, 1890-Accepted, 28th June, 1890
COMPLETE SPECIFICATION,
Improvements in Linkages for Transmitting Motion.
I JAMES PLAISTER HARRISS GASTRELL., domiciled in Nassau, Germany, and resident
therein at No. 2 Theodoren Strasse, Wiesbaden, but temporarily residing in Chicago,
Illinois, United States of North America, do hereby declare the nature of this inven-
tion and in what manner the same is to be performed, to be particularly described and
ascertained in and by the following statement:
The object of my invention is to construct an improved mechanical movement by
which a reciprocating motion is converted into a rotary motion, or a rotary motion
converted into a reciprocating motion, by which means the distance between the head
of the reciprocating portion and the pin of the crank is greatly reduced, and by which
means machines in which the crank is used with a connecting rod are made more com-
pact, as fully described hereafter, reference being had to the accompanying drawings,
in which Figs. 1, 2, 3, 4, and 5 are diagram views illustrating the movement of the
mechanism.
If, for instance, the movement is applied to engine in which the reciprocating
motion is represented by the piston rod, and the rotary motion by the crank, I connect
to the head P of the piston rod, two long links 11, 11, by the pivot pin l, and to the
wrist pin WP of the crank, two short links s 1, s. These links are connected to the
long links by pivot pins el, cl, and pivoted to these pins are short links & l', sl,
which are connected together and to a link i by a pivot pin el; this link i is pivoted to
the head P by a pin f, as clearly shown in Fig. 1 of the drawing. All the links are
free to move on their centres or pivots. If the head P is moved in the direction of
the arrow Fig. 1, and the wrist pin moves over the centre of the circle indicated by
dotted lines, and in the direction shown by the arrow, the tendency of the mechanism
will be to force the links pivoted at el down in the direction of the arrow, and the
links pivoted at clout, as indicated by the arrow, thus forcing the wrist pin in the
circular course, as will be clearly understood in following out the movements of the
different parts, as indicated in the diagrams Figs. 2 & 3.
When the wrist pin reaches the quarter turn or half stroke Fig. 3, the tendency of
the device is to still draw the links centred on the pivot cl down, and the links
centred on the pivot cl in an inclined line, as shown by the arrow, until the full stroke
is reached, as shown in Fig. 4, and the wrist pin has travelled one half of its revolu-
tion. On the return stroke, the above described movements are reversed, as is clearly
shown in Fig. 5.
I am thus enabled to connect a reciprocating rod or head to a crank or wrist pin by
a series of short links, dispensing with the usual long connecting rod. My invention
can be applied to any machine in which a reciprocating motion is transformed into a
rotary motion, and in an engine the mechanism may be attached to the valve operating
devices, as well as to the piston rod and crank.
It will be understood that the several links shown may be of different length and
proportion, depending altogether upon the construction of the apparatus to which the
invention is applied.
It will be understood that the crank carrying the wrist pin can be rotated, and
reciprocating motion imparted to the head, as would be the case in operating valve
gears and similar mechanism.
Having now particularly described and ascertained the nature of the said invention
and in what manner the same is to be performed, I declare that what I claim is :—
The combination of the reninzcenting boad limbs 1 11
Lad

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at the same point with a wrist pin or crank, two links s 1³, sl, pivoted to said wrist
pin, and pivoted at their outer ends respectively to the links ,, with links
sl, sl, also pivoted to both pairs of links mentioned, and pivoted at their inner ends
to each other, and to a link i, which is pivoted to the head at its opposite end, the
whole acting substantially as described on the reciprocation of the head or rotation of
the crank.
NEWTON & SON,
Agents for the Applicant.