Improvements in the Construction of Compound and Multiple Compound Steam Engines.
Year: 1895

page_text: Date of Application, 13th Mar., 1895
Complete Specification Left, 12th Dec., 1895-Accepted, 18th Jan., 1896
PROVISIONAL SPECIFICATION.
Improvements in the Construction of Compound and Multiple
Compound Steam Engines.
CHARLES SCOTT of Guide Bridge Iron Works Hooley Hill Engineer HENRY
HODGSON, Guide Bridge Iron Works Hooley Hill Engineer do hereby declare the
nature of this invention to be as follows:-
The arrangement of two or more cylinders of vertical or horizontal engines at
right angles with the axis of the crank shaft, the piston rods being coupled by
links to a lever to which the connecting rod is also attached. 2nd. Or the piston
rods may be attached to a T shaped crosshead, the lower end of the crosshead
being guided by a parallel motion of the usual construction. 3rd. Or the piston
rols may be coupled to the two radius bars of a Z parallel motion by links, the
connecting rod being attached to the middle bar.
Dated this 12th day of March 1895.
CHARLES SCOTT.
HENRY HODGSON.
J
Improvements in the Construction of Compound and Multiple
Compound Steam Engines.
We, CHARLES SCOTT and HENRY HODGSON of Guide Bridge Iron Works,
Hooley Hill, Cheshire, Engineers, 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 :-
.J
Our invention consists of engines with vertical or horizontal cylinders in which
the plane containing the centre lines of the cylinders is at right angles to the centre
line of the crank shaft, and in carrying out our invention we connect the piston rods
of the cylinders to the crank by one or other of the arrangements of link and lever
apparatus hereinafter described or any mechanical equivalent thereof and it will be
understood that our invention can be applied either to engines in which both
cylinders are what is known as high pressure or to compound engines or to triple
or quadruple engines as hereinafter described.
In order that our invention may be better understood we refer to the accom-
panying drawings, in which Figs. 1, 2, and 3 represent the three leading forms in
which our invention can be applied.
A and B are the two cylinders of which in a compound engine the smaller, A, is
the first or high pressure cylinder, and the larger, B, is the second or low pressure
cylinder. The latter has also in this case a longer stroke. is the entablature
and D D are the standards of the engine frame. The piston rods E and E' are
secured to crossheads F and F and slippers G and G' in the ordinary manner, the
slippers working in the usual slides H and H. The short links I and I connect
the crossheads F and F' to the strong lever or beam K pivotted on a fixed centre
or bearings L which may or may not be external to the frame of the engine. At
or about midway between the centres of attachment of the links I and I' we attach

page_text: the connecting rod M operating the crank N in the ordinary way. In pairs of
engines the above described apparatus is duplicated and the two cranks can then
be placed at or about half-centres to balance the parts. Or we can also construct
triple expansion engines by treating the cylinder B as the second or intermediate
cylinder and placing one low pressure cylinder centrally over the crank shaft
operating a separate crank in the ordinary way. Or in cases in which this cylinder
would become too large we can use two low pressure cylinders of equal size
operating their crank through the medium of a beam or lever corresponding in all
respects to the arrangement herein before described and illustrated as for a compound
engine. In this latter case we prefer to make one distributing valve control the
steam and exhaust from both the said low pressure cylinders.
In condeusing engines we make use of the beam K to operate the air pump.
The second form of our invention is illustrated in Fig. 2. A and B are as before
the two cylinders whose centre lines are in a plane at right angles to the crank
shaft n.
The strokes of the cylinders in this case are equal. The piston rods E
and E are rigidly attached to a special T shaped crosshead F whose ends carry
the slippers G and G¹ working in the guides Hand H. The connecting rod M is
attached to the crosshead F at f and operates the crank N. If the force exerted
by either piston were in excess of the other there would be a tendency to remove
the crosshead F from the horizontal position and hence to bind or jam the slippers
in the guides. In order therefore to retain the crosshead in its true position we
construct it with a projection f¹ forming a T" and to the end of the projection
we pivot the centre o of the middle bar O of a parallel motion of which P and P¹
are the radius arms, having their centres at p and p' which may or may not be
carried by a portion of the engine frame. The pivot o being thus constrained to
move in a straight line parallel with the slides, and as the slippers are constrained
by the slides to also travel in a parallel line there can be no binding or untrue
movement of the crosshead. The radius arms P and P¹ convey no part of the
driving force of the engine, but either or both can be utilised to operate an air or
other pump.
In this application of our invention the engine can also be balanced
by employing a second pair of cylinders and it is also applicable to simple,
compound, triple or quadruple expansion engines either high pressure or
condensing.
The third form of our invention is illustrated in Fig. 3 :-A and B are the
cylinders as before, E and E' their piston rods and F and F¹ the crossheads which
in this case are independent, as in the first form and are guided by the slippers G
and G' working on the slides H and H'.
AZ parallel motion having the radius arms P and P¹ and middle bar O
is mounted as shewn on centres p and p' self-contained in the engine frame or
otherwise. The two crossheads are linked to the radius arms P and P' by the
short links I and I' and the connecting rod M is pivotted to the centre of the
middle bar O ato and operates the crank N. The extremes of movement of
the radius arms are indicated by the dotted lines. It will be understood that the
radius arms are practically beams of sufficient strength to transmit the working
strain of the cylinders from the crossheads to the middle bar O and so to the
connecting rod. In this form also the engine can be balanced by being duplicated
and is also applicable as a simple, compound, triple expansion or quadruple
expansion engine either high pressure or condensing. Either or both of the radius
arins can be made use of to operate air or other pumps.
Having now particularly described and ascertained the nature of our said inveu-
tion, and in what manner the same is to be performed we declare that we
claim is :-
1. The construction of engines whose plane of cylinders is at right angles to the
crank shaft, and whose cylinders in the same plane operate one crank, being coupled
thereto by the links and rocking beam or beams, substantially as and for the
purposes herein before described and illustrated in the accompanying drawings.

page_text: 2. The rocking beam or lever to which the crossheads of two or more cylinders
are attached by links and having the connecting rod of the engine pivotted to it,
substantially as and for the purposes hereinbefore described and illustrated in the
accompanying drawings.
3. The construction of engines whose plane of cylinders is at right angles to the
crank shaft and whose cylinders in the same plane operate one crank being coupled
thereto by a T shaped crosshead substantially as and for the purposes herein before
described and illustrated in the accompanying drawings.
4. Parallel motion applied to constrain one end of a T shaped crosshead to travel
in a parallel line with the guides of an engine in which two or more piston rods are
connected to the said crosshead and to which crosshead the connecting rod is also
pivotted, substantially as and for the purposes herein before described and illustrated
in the accompanying drawings.
5. The parallel motion to whose radius arms the crossheads of two or more piston
rods are attached by links, and to whose middle bar the connecting rod of the
engine is pivotted substantially as and for the purposes hereinbefore described and
illustrated in the accompanying drawings.
6. Balanced engines working with either simple or multiple expansion in com-
bination with any of the hereinbefore described arrangements of link and lever
connecting gear substantially as and for the purposes hereinbefore described.
Dated this 11th day of December 1895.
EDGAR CONISTON MILLS,
Agent to the Applicants.