IMPROVEMENTS IN ENGINES WORKED BY COMPRESSED AIR
Year: 1877

page_text: LETTERS PATENT to James Stear, of the Strafford Collieries, Barnsley, Engineer,
and William Daniel, of the Steam Plough Works, Leeds, Engineer, both in the
County of York, for the Invention of "IMPROVEMENTS IN ENGINES WORKED
BY COMPRESSED AIR."
Sealed the 1st September 1877, and dated the 12th March 1877.
$
PROVISIONAL SPECIFICATION left by the said James Stear and William
Daniel at the Office of the Commissioners of Patents on the 12th March
1877.
JAMES STEAR, of the Strafford Collieries, Barnsley, Engineer, and WILLIAM
DANIEL, of the Steam Plough Works, Leeds, Engineer, both in the County of York.
IMPROVEMENTS IN ENGINES WORKED BY COMPRESSED AIR."
This Invention has for its object to construct the valve gear of engines worked
by compressed air in such a manner that the formation of ice in the ports is
prevented. This is accomplished by allowing the exhaust air to discharge direct
into the atmosphere at each end of the cylinder, the valve or valves being worked
by eccentrics in the usual manner or by tappets, or from the cross head or by other
methods.
SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said James Stear and Willian Daniel in the Great Seal Patent Office on
the 12th September 1877.
JAMES STEAR, of the Strafford Collieries, Barnsley, Engineer, and WILLIAM
DANIEL, of the Steam Plough Works, Leeds, Engineer, both in the County of York.
"IMPROVEMENTS IN ENGINES WORKED BY COMPRESSED AIR."
This Invention has for its object to construct the valve gear of engines worked
by compressed air in such a manner that the formation of ice in the ports is
prevented. This is accomplished by allowing the exhaust air to discharge direct
into the atmosphere at each end of the cylinder, the valve or valves being worked
by eccentrics in the usual manner or by tappets, or from the cross head or by other
methods.
.

page_text: The Drawings hereunto annexed shew various constructions of valve gear for
engines worked by compressed air arranged as above described.
DESCRIPTION OF THE DRAWINGS.
Figures 1, 2, and 3 show one construction of the valve gear; Figure 1 is an
elevation of the cylinder of an air engine aud its valve face, shewing the inlet and
exhaust ports; Figure 2 is a cross section; and Figure 3, a longitudinal section
through the cylinder and ports. In this arrangement the compressed air is admitted
through the passage A to the recesses B' in the under side of the slide valve B; when
the piston of the engine has arrived at the end of its stroke, the slide valve B, which
is worked by an eccentric, has passed over one or other of the exhaust ports C, and
so allowed the air to escape from the cylinder without passing through the inlet
ports A.
Figures 4 and 5 shew a similar arrangement, except that the slide valve works
through a stuffing box. The compressed air is adınitted into the chamber A. through
which passes the slide valve B, a tight joint being made around the valve by cupped
packings C; the valve is hollow and air passes into it from the chamber A through
the openings D. The ends of the slide valve B work as shewn against fixed valve
faces E formed at the side of the cylinder G of the engine. Ports are formed in the
ends of the valve B through which the compressed air is supplied alternately to the
two ports H in the valve face at the two ends of the cylinder. When the piston
arrives at the end of its stroke the slide valve has passed beyond one or other of the
ports H, and so allowed air to escape from that end of the cylinder.
Figures 6, 7, 8, 9, and 10 shew an arrangement in which in addition to employing
a slide valve for admitting compressed air alternately to the two ends of a cylinder
other exhaust valves are used on each cylinder cover, and these exhaust valves are
actuated from the valve spindle working the slide valve. A is the slide valve
spindle with a cross head B fastened to it, which alternately strikes the levers C
and C, and so gives a to-and-fro movement, as shewn, to the rotating exhaust
valves D which are at the two ends of the cylinder; detail views of these valves are
shewn at Figures 8, 9, and 10.
Having thus described the nature of our Invention, and the manner of performing
the same, we would have it understood that we claim,―
First. Constructing the valve gear of engines worked by compressed air in such
manner that the exhaust air is discharged direct into the atmosphere at each end
of the cylinder, as herein described, to prevent the formation of ice in the ports.
Second. The arrangements of valve gear for engines to be worked by compressed
air, substantially as herein described and shown by the Drawings annexed.
In witness whereof, I, the said William Daniel, have hereunto set my hand
and seal, this Tenth day of September, in the year of our Lord One thousand
eight hundred and seventy-seven.