Improvements in the Construction of Cylinders of Steam and other Fluid Pressure Engines or Apparatus and in the Means for Distributing the Actuating Fluid therein.
Year: 1887

page_text: Date of Application, 31st Dec., 1887
Complete Specification Left, 29th Sept., 1888
Complete Specification Accepted, 2nd Nov., 1888
Improvements in the Construction of Cylinders of Steam and
other Fluid Pressure Engines or Apparatus and in the Means
for Distributing the Actuating Fluid therein.
I, DAVID PURVES of "Ferro Dene" Green Lane, North Dulwich, in the County
of Surrey, Engineer, do hereby declare the nature of this invention to be as
follows:-
This invention relates to that class of cylinder and valve in which steam or other
motive power pressure is commonly employed.
The invention consists in the improved construction and arrangement of parts as
hereafter set forth, it being assumed for the purpose of illustration that the invention
is applied in a double pressure steam cylinder. In this case the outer cylinder
terminates at each end in a cylindrical steam chest or box provided with suitable
internal ports. The steam supply pipe being branched so that said chests or boxes
practically form the ends of the pipe. The cylinder between said ends is recessed
leaving a cylindrical space between the outer cylinder and the inner lining which
according to my invention forms the piston cylinder and slide valve at the same time
and is caused to travel over the steam ports of the chests or boxes in manner and by
means analogous to those employed for ordinary slide valves said inner cylinder being
provided with ports adapted to correspond with those in the chests or boxes and
when suitably moved, to open into the cylindrical space between the cylinders and
thence to exhaust.
Dber 1987
PHILIP M. JUSTICE,
55 & 56, Chancery Lane, London;
Applicant's Agent.

page_text: Improvements in the Construction of Cylinders of Steam and
other Fluid Pressure Engines or Apparatus and in the Means
for Distributing the Actuating Fluid therein.
I, DAVID PURVES of "Ferro Dene," Green Lane, North Dulwich in the County
of Surrey, Engineer, 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 :-
This invention relates to that class of cylinder and valve in which steam or other
motive power pressure is commonly employed.
The invention consists in the improved construction and arrangement of parts as
hereafter set forth, reference being made to the accompanying drawings which form
part of this specification and which show the invention applied in a double pressure
steam cylinder, Fig. 1 being a sectional elevation, Fig. 2 a cross section on the
linea, and Fig. 3 a cross section on the line y y. In this case the outer cylinder A
terminates at each end in a cylindrical steam chest or box a a¹ provided with suitablo
internal ports. The steam supply pipe may be branched so that said chests or boxes
practically form the ends of the pipe or as shown in the drawings the steam supply
through A¹ opens directly into the chests a a¹. The cylinder A between said ends is
recessed leaving a cylindrical space B between the outer cylinder A and the inner
lining C, which according to my invention forms the piston cylinder and slide valve
at the same time, and is caused to travel over the steam ports b¹ of the chests or
boxes a a¹ in manner and by means analogous to those employed for ordinary slido
valves. In the drawings said inner cylinder is intended to be operated by rods d d
which pass through suitable stuffing boxes, further description of the method of
attachment and operation being deemed unnecessary. The inner cylinder
provided with ports e e¹ adapted to correspond with those in the chests
or boxes a a¹, and when suitably moved, to open into the cylindrical space B between
the cylinders and thence to exhaust D.
is
For making steam tight bearings the chests a a¹ may be provided with packing
rings EE cut diagonally across and held by clamps FF which will prevent any
rotary movement and yet allow of adjustment for wear, all as most clearly shown
in Fig. 3.
Although the invention has been described as applied to steam pressure engines
it will be evident that it is equally applicable for gas air or other fluid pressure, and
it will be also obvious that the cylindrical space B may be used as the pressure inlet,
while chests a a' may be used as the exhaust ports.

page_text: Having now particularly described and ascertained the nature of my said inven-
tion, and in what manner the same is to be performed, I declare that what I
claim is:
1st. The herein before described improvements in the construction of cylinders of
steam and other fluid pressure engines or apparatus consisting of the combination with
the piston of a movable cylinder liner provided with suitable ports adapted to
alternately open to inlet and exhaust substantially as set forth.
2nd. The herein before described improvements in the means of distributing the
actuating fluid pressure in the cylinders of steam or other fluid pressure engines
which consists of the combination with the piston of an internal movable liner
provided with suitable ports and an external cylinder also provided with suitable inlet
and exhaust ports substantially as set forth.