IMPROVEMENTS IN APPARATUS FOR DISTRIBUTING STEAM, OR OTHER FLUID UNDER PRESSURE, IN MOTOR ENGINES
Year: 1882

page_text: PROVISIONAL SPECIFICATION left by John Weston Jordan and John
Thomas Brockliss at the Office of the Commissioners of Patents on the
21st November 1882.
JOHN WESTON JORDAN and JOHN THOMAS BROCKLISS, of Norwich, in the
County of Norfolk, Engineers, "IMPROVEMENTS IN APPARATUS FOR DISTRIBUTING
STEAM, OR OTHER FLUID UNDER PRESSURE, IN MOTOR ENGINES,"
Our Invention relates more particularly to the means for controlling and
regulating the admission and release of steam or other fluid under pressure to and
from the cylinders of oscillating engines; our object being to obtain greater
simplicity and economy in construction than commonly appertains to apparatus for
accomplishing the purposes referred to.
In applying our Invention to an oscillating engine, we mount the steam cylinder
on two trunnions placed one on each side of the cylinder and having a common
axis at right angles to that of the cylinder. One of these trunnions may be formed
on or attached to the cylinder body and the other arranged on the exterior of the
valve casing or jacket, the steam inlet and exhaust outlet passing through the said
trunnions respectively; or if preferred, communication may be effected through
the main bearings with the trunnions laterally.
Steam or other fluid under pressure, having found its way to the interior of the
valve casing or jacket, is distributed by means of apparatus and passages of the
following construction and arrangement. Each end of the cylinder is in com-
munication by means of a passage with an opening or port in a surface working in
contact with a distributing valve. This latter is by preference of the "face-valve "
type, and is carried concentrically with the trunnions by means of a stem at the
back. The valve may consist of a complete disc with suitable openings through it;
but, with a view to reducing friction, we prefer a form which may be approximately
described as constituted by two segments of a disc radiating from opposite sides of
a central enlargement or trunk. Each of these segments or arms presents a surface
which alternately covers and uncovers the port of the cylinder passage as the
cylinder oscillates. Each arm is further provided with a passage communicating
with the exhaust outlet, which passage arrives at suitable periods opposite the
port of the cylinder passage and permits the steam or fluid which has done its
work to escape.

page_text: In constructing a valve for an oscillating engine, the direction of running whereof
is intended to be reversible, we form one arm of the valve with two radial exhaust
passages arranged one on each side of a steam orifice through the valve. The
other arm of the valve is formed with a radial exhaust passage in the centre and
a certain width of cover on each side thereof. We mount such a valve in a manner
which will permit of its being partially rotated on its axis and the positions of its
covering surfaces and passages varied relatively to those of the cylinder ports.
On the valve being slightly rotated the attributes of the valve motion known as
"lead and lap" are increased. On arrival of the valve at mid-stroke, the passages
to both ends of the cylinder are cut off from the steam supply and the engine stops.
On the movement being continued, the distribution of the steam becomes such
that the crank-shaft of the engine is caused to rotate in the opposite direction to
that which originally prevailed.
It will be readily understood that the method of construction described might be
adapted to a cylinder which is fixed instead of oscillating; the valve being caused to
vibrate about its central axis. The engine would, however, in this case, be provided
with crosshead, guide and connecting rod in the usual manner.