Improvements in Connecting Rods or like Devices.
Year: 1899

page_text: Date of Application, 27th July, 1899 -Accepted, 9th Sept.,
1899
COMPLETE SPECIFICATION.
Improvements in Connecting Rods or like Devices.
I, ROBERT GEORGE LINN, of Sawdust Valley, Maury County, in the State of
Tennessee, United States of America, Gentleman, do hereby declare the nature
of this invention and in what manner the same is to be performed, to be
particularly described and ascertained in and by the following statement : —
The invention relates to improvements in pitmen.
The object of the present invention is to improve the construction of that class
of pitmen employing a lazy tong arrangement of levers, and to provide a simple
one, capable of transmitting the full measure of power on a crank as long as the
stroke of the piston.
The invention consists in the construction and novel combination and arrange-
ment of parts, as hereinafter fully described, illustrated in the accompanying
drawings and pointed out in the claims hereto appended.
In the drawings:-
Figure 1 is a perspective view of a pitman constructed in accordance with
this invention.
Figure 2 is a longitudinal sectional view.
Figure 3 is a plan view of a portion of the pitman, illustrating the arrange-
ment of the oscillating arms and bars.
Like numerals of reference designate corresponding parts in all the figures
of the drawings.
1 designates a cross-head of a piston-rod 2, mounted in suitable guides or
ways 3, and connected by a lazy tong system of levers with a crank 4, of a shaft 5,
upon which is mounted a fly wheel 6, but instead of connecting the lazy tong
system of levers with a crank, it may be pivoted to a wrist pin of a drive wheel
or pulley, as will be readily understood. One end of the system of levers is
connected directly to the cross head 1, and the other end of the system is similarly
connected to the crank 4, and this direct arrangement enables the full power of
an engine to be transmitted to the machinery to be operated.
The lazy tong system of levers comprises the short levers 12 and 14, which are
pivoted at their outer ends to the cross-head, the long levers 16 and 17, the
connecting bars 13 and 15, and the toggle links 18 and 19, extending from the
outer ends of the levers 16 and 17, to the crank. The inner ends of the levers 12
and 14 are pivotally connected to the inner terminals of the long levers 16
and 17, which are fulcrumed at 16ª, at a point between their ends, and the said
levers 12 and 14 are pivotally connected or fulcrumed at points between their ends
at 12 and 14ª, on the adjacent ends of the connecting bars 13 and 15, which
centrally cross each other, being disposed parallel with the levers 12 and 14,
respectively.
The levers 12 and 14 are twice the length of the stroke of the piston, the
distance between the pivot points of these levers being equal to the length of
the stroke, and the levers 16 and 17, which are not pivoted to the adjacent ends
of the bars 13 and 15, have their longer arms twice the length of the strokes and

page_text: their shorter arms are of the same length as the stroke. The cross-head is prefer-
ably provided with a recess to receive the adjacent ends of the levers 12 and 14,
and the levers 12 and 17, and the bar 13 and toggle link 18,, which are parallel
with one another, are preferably duplicated and located at opposite sides of the
other members of the lazy tong system of levers. The distance between the pivots
of the bars 13 and 15 is equal to the length of the stroke of the piston.
As the piston reciprocates, the lazy tong system of levers expands and contracts
incident to the rectilinear movement of the cross-head, and it is vibrated or
oscillated vertically through the rotation of the crank 4. In order to accomodate
the system of levers to this oscillatory movement, a swinging or oscillating
fulcrum is provided, and it consists of a transverse rod 7, passing centrally through
the cross bars 13 and 15, and a pair of oscillating bars or arms 9, which are
connected with the frame or support 8, at a point opposite the pin of the cross-
head when the same is midway the length of the stroke. The arms 9 oscillate on
the pivot 11 to accomodate the fulcrum rod to the vertical movement of the lazy
tong system of levers, and by connecting the same directly to the cross-head and
to the crank, the intermediate connecting rod, usually employed, at one end or
the other, of the system of lazy tong levers, is dispensed with, and the leverage
is rendered more direct. The oscillating bars are one and one-third times the
length of the stroke of the cross-head, and the oscillating fulcrum rod is located
twice the distance from the crank that it is from the cross-head.
The invention has the following advantages:
The lazy tong system of levers, which is connected directly to the cross-head
and the crank, dispenses with the connecting rod usually employed in such
arrangement and transmits the full measure of the power on a crank as long as
the stroke of the piston. The swinging fulcrum oscillates vertically with the lazy
tong system of levers and by duplicating the members, as before described, the
strain on the pivots is equalized and is central, so that there is no liability of the
pivots twisting..
Having now particularly described and ascertained the nature of my said
invention and in what, manner, the same is to be performed, I declare that what
I claim is:
1. In a device of the class described, the combination of a lazy tong system
of levers designed to be connected with a cross-head and comprising the short
levers 12 and 14 pivoted together at their outer ends, the long levers 16 and 17
pivoted together near their outer ends and having their inner terminals connected
to the inner ends of the levers 12 and 14, the crossed bars 13 and 15 pivoted
to the levers 12 and 14 at the centers thereof, and the toggle links connected
with the outer ends of the levers 16 and 17, and an oscillating or swinging
fulcrum connected with the bars 13 and 15, substantially as described.
2. In a device of the class described, the combination of the short levers 12
and 14, pivoted together at their outer ends and designed to be connected with
a cross-head, the long levers 16 and 17 pivoted together near their outer ends
and having their inner terminals connected with the inner ends of the short
levers, the toggle links arranged at an angle to the outer portions of the long
levers, pivoted to the same and having their outer ends pivotally connected
together and designed to be attached to a crank, and an oscillating fulcrum
connected with the levers, substantially as described.
3. In a device of the class described, the combination of the short levers 12
and 14 pivoted together at their inner ends and designed to be connected with a
cross-head, the long levers fulcrumed between their ends and having their inner
ends connected with the short lever and designed to be connected at their outer
ends with a crank, bars pivoted to the short levers at points between the ends
thereof, and an oscillating fulcrum or support passing through the said bars,
substantially as described.
4. In a device of the class described, the combination with a reciprocating

page_text: cross-head, of a lazy tong system of levers comprising the short levers 12 and 14
pivoted at their outer ends to the cross-head, the long levers 16 and 17 pivoted
together near their outer ends and having their inner terminals pivoted to the
inner ends of the levers 12 and 14, the crossed bars 13 and 15 pivoted to the
levers 12 and 14, at the centers thereof, and the toggle links connected with
the outer ends of the levers 16 and 17, and an oscillating or swinging fulcrum
passing through the bars 13 and 15 and connecting the same at the centers
thereof, substantially as described.
lay of July 1899.
For the Applicant,
J. G. LORRAIN, M.I.E.E., M.I.Mech. E,.
Norfolk House, Norfolk Street, London, W.C.,
Chartered Patent Agent.