IMPROVEMENTS IN STEAM ENGINES
Year: 1879

page_text: LETTERS PATENT to John Walker, of Roundhay Road, Leeds, in the County
of Yorkshire, Engineer, and Thomas Thompson, of the Cedars, Sunderland, in
the County of Durham, Engineer, for the Invention of "IMPROVEMENTS IN
STEAM ENGINES."
Sealed the 16th March 1880, and dated the 16th October 1879.
PROVISIONAL SPECIFICATION left by the said John Walker and Thomas
Thompson at the Office of the Commissioners of Patents on the 16th October
1879.
JOHN WALKER, of Roundhay Road, Leeds, in the County of Yorkshire, Engineer,
and THOMAS THOMPSON, of the Cedars, Sunderland, in the County of Durham,
Engineer. "IMPROVEMENTS IN STEAM ENGINES."
Our Invention relates to improvements in steam engines, whereby great power
is obtained in a small space with simplicity in the construction of the working
parts.
In carrying out our Invention we employ in combination three, six, or any other
convenient number of double acting steam cylinders, radiating from a centre, the
junction of which cylinders forms a cavity through which the crank shaft passes.
On the crank pins are fitted star wheels or discs, the arms of which are connected
by links to the rear ends of the piston rods, the star wheels or discs being provided
with wings which work in a suitable groove. The slide valves are all operated
and reversed as required from one annular groove or slot of an eccentric or cam
shape, or of any other required form, the ends of the slide rods engaging in the said
groove or slot.
Our Invention is applicable both to simple and compound engines.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said John Walker and Thomas Thompson in the Great Seal Patent Office
on the 16th April 1880.
JOHN WALKER, of Roundhay Road, Leeds, in the County of York, and THOMAS
THOMPSON, of the Cedars, Sunderland, in the County of Durham, Engineers.
"IMPROVEMENTS IN STEAM ENGINES."
Our said Invention relates to improvements in steam engines whereby great
power is obtained in a small space with simplicity in the construction of the working
parts.
In carrying out our Invention we employ in combination three, six, or any other
convenient number of double acting steam cylinders, radiating from a centre, the
junction of which cylinders forms a cavity through which the crank shaft passes.
On the crank pins are fitted discs which are connected by rods to the rear ends of
the piston rods. The slide valves of the cylinders are all operated as required from
one annular groove or slot formed in a disc, which is keyed upon the crank shaft,
the ends of the valve rods engaging in the said groove or slot.
And in order that our said Invention may be fully understood we shall now
proceed more particularly to describe the same, and for that purpose shall refer to the
several Figures on the annexed Sheet of Drawings, the same letters of reference
indicating corresponding parts in all the Figures.
The
Figure 1 of the accompanying Drawings represents a side elevation of a triple
cylinder double acting steam engine constructed according to our said Invention.
Figures 2 and 3 are respectively a section and end elevation of the same.
remaining Figures are detail views of parts and modifications of parts of our
improvements. The engine in the example illustrated consists of three double
acting steam cylinders A which are employed in combination, and which radiate
from a centre, the junction of the cylinders forming a cavity through which the
crank shaft B passes.
On the crank pins b of the cranks b' are fitted the discs C, which are connected
by rods D to the rear ends of the piston rods a, the said rods D at one extremity
working in pins on the said piston rods, and at their other extremities being
connected to the discs C in the following manner :- -One of the connecting rods
(marked D*) is screwed or otherwise attached rigidly to its disc. The other rods D
are connected to and work upon pins which pass through holes in the said discs,
shewn more particularly in Figures 4 and 5.
A modification in the manner of connecting the ends of the rods D to the discs
C is shewn in Figures 6 and 7, in which the ends of the said rods are in direct
contact with the crank pins b, the said rods being kept in their respective positions
by forming their ends with semi-circular or other conveniently shaped cross pieces d
which work in correspondingly shaped apertures in the two sides or halves c' of
the disc, whilst the said sides or halves are held together by means of the pins c².
The discs may be constructed so as to box in or enclose the inner ends of the
connecting rods in a manner which will be perfectly understood without
illustration.
The slide valves of the cylinders are not shewn in the Drawing, but they may be
of any ordinary or suitable description. They are all operated as required from
one annular groove or slot e of an eccentric or cam shape, or of any other required
form, the said groove or slot being formed in a disc E which is keyed upon the
crank shaft B, the ends of the valve rods e¹ engaging in the said groove or slot, as
shewn in Figure 1, and in the detail views, Figures 8 and 9. Although we have
shown in the Drawing a three cylinder steam engine with our improvements com-
bined therewith, we do not limit ourselves to that particular number of cylinders,
as six, or any other convenient number of cylinders, may be employed.

page_text: Having now described and particularly ascertained the nature of our said
Invention, and the manner in which the same is or may be used or carried into
effect, we would observe in conclusion that what we consider to be novel and
original, and therefore claim as the Invention secured to us by the herein before in
part recited Letters Patent is,
The combination in a steam engine of multiple double acting cylinders radiating
from a common crank shaft with the peculiar valve gear herein set forth, the
whole of the parts being arranged and combined together, substantially in the
manner herein before described.
In witness whereof, we, the said John Walker and Thomas Thompson, have
to this our Specification set our hands and seals, this Eighth day of April,
One thousand eight hundred and eighty.
JOHN WALKER.
(L.S.)
THOMAS THOMPSON. (L.S.)