IMPROVEMENTS IN APPARATUS FOR IGNITING THE CHARGES OF GAS MOTOR ENGINES
Year: 1878

page_text: PROVISIONAL SPECIFICATION left by Charles Denton Abel at the Office of
the Commissioners of Patents on the 2nd May 1878. A communication from
abroad by Nicolaus August Otto, of the Gasmotoren Fabrik-Deutz, at Deutz,
in the German Empire.
CHARLES DENTON ABEL of No. 20 Southampton Buildings Chancery Lane in
the County of Middlesex. "IMPROVEMENTS IN APPARATUS FOR IGNITING THE
CHARGES OF GAS MOTOR ENGINES." [A communication from abroad by Nicolaus
August Otto, of the Gasmotoren Fabrik-Deutz, at Deutz in the German Empire.]
This Invention has reference to the use of the electric spark for igniting the
charges of gas motor engines, and consists in the use for this purpose of the spark
produced by the interruption of a current generated in the closed circuit of the coil
of an armature revolving or oscillating between the poles of one or more magnets.
The armature may be made to revolve continuously and the positions of its coils
relatively to the magnets be so adjusted relatively to the motion of the engine that
the current generated will be at its strongest when the gaseous charge has been
admitted to the cylinder and it is desired to ignite it by the spark. By preference
however the armature has only a rapid oscillating motion imparted to it at the time
when it is required to produce the current for the spark. For this purpose various
arrangements of the apparatus may be employed; according to the arrangement
employed, by preference a "Siemens" armature, namely a grooved cylinder having
coils wound longitudinally upon it is mounted on an axis between the poles of a
magnet, the one terminal of the coil being electrically connected to an insulated
contact point inside the cylinder while the other terminal is connected to a con-
ducting disc on the axis of the armature, against which bears an arm on an insulated
spindle passing through the cylinder and having at its inner end a finger in contact
with the before-mentioned contact point. The axis of the armature also carries an
arm connected by a link to one end of a bell-crank lever, the other end of which
bears against a cam on a shaft to which rotary motion is imparted by the engine.
This cam is formed with a sudden drop so that during its revolution it first moves
the lever and thereby also the armature to a certain extent in one direction and
[Price 2d1 16485.

page_text: then causes it to move back suddenly into its original position, by which sudden
partial revolution a current is generated in the coil of the armature, and at the
moment when this current has attained its greatest strength, which is made to
coincide with the moment when the combustible charge has been introduced into
the cylinder a projection on the before-mentioned disc of the armature against
which the contact arm bears moves the latter so as to bring the finger at the other
end of its spindle out of contact with the fixed contact point, thereby producing the
spark for igniting the charge.
The currents from the revolving or oscillating armature might be passed by a
commutator into a condenser, the electrodes of which are connected to the before-
mentioned fixed and moveable contact points which in this case would .be kept
apart until the spark is required, this being produced by bringing the contact points
together. It is preferred however for the sake of simplicity of construction to
employ the first-described arrangement.