Year: 1887

page_text: Date of Application, 30th Aug., 1887.
Specification Accepted, 4th Oct., 1887
Cylinder.
I ARTHUR HERBERT WALLIS of Wallis & Steevens Engineers North Hants Iron
Works Basingstoke England 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 consists in the peculiar construction of a cylindrical chamber
jacketted with steam, attached to the cylinder, & having working in it a cylindrical
projection attached to the piston; constructed and combined in the manner herein
described by reference to the attached drawing.
A is a jacketted cylinder.
B is a steam chest.
C is the high pressure steam port communicating from the steam chest into the
cylinder.
D is the low pressure steam port communicating from the steam chest into the
cylinder.
.
E is the exhaust port communicating from the steam chest to an exhaust pipe.
F is a D slide valve of the shape shown, and is worked backwards and forwards by
an eccentric on the crank shaft of the engine in the usual manner.
G is a piston working in the cylinder A.
His a cylindrical projection of less diameter than the piston, & cast on to the
piston as shown, or otherwise attached.
It is evident that the projection H reduces the area of the piston on the side to
which it is attached.
I is a ring of packing.
J is a gland.
K is a circular collar fitting by a thread on to the end of H as shown, and having
holes in it into which a key fits for turning it. It is evident that as the collar K is
screwed on to H the gland J is forced inwards thus compressing the packing I.
The piston is connected by the crosshead L to a connecting rod which works on
the engine crank shaft in the usual manner.

page_text: M is a cylindrical chamber cast on or otherwise attached to the cylinder A and
surrounded by a steam jacket N. The cylinder A is also partially surrounded by a
steam jacket O and this communicates with the steam jacket N or the steam jacket N
may be connected direct to the boiler.
The cylindrical chamber M attached to the cylinder is parallel with it, and of such
internal diameter that the projection H attached to the piston fits it; the packing
ring I preventing any escape of steam from the cylinder in that direction.
The action of the engine is as follows:-the steam passes from the steam chest B
through the port Cinto the cylinder at the high pressure end thus giving the high
pressure stroke; it then returns through the port C and the cavity in the valve F and
passes down the port D into the low pressure end of the cylinder, producing the
return or low pressure stroke; the steam then exhausts through the port D and the
cavity in the valve F into the exhaust port E.
In place of the packing I metal rings or other suitable arrangement for preventing
the passage of steam may be used.
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,
The construction of a cylindrical chamber jacketted with steam, attached to the
cylinder, and having working in it a cylindrical projection attached to the piston ;
constructed and combined in the manner herein described.
Dated this 27th day of August 1887.