ignition apparatus with stationary armature for gas engines
Year: 1897

page_text: I, ROBERT BOSCH, of 108 Rothebühl Strasse Stuttgart in the Kingdom of
Wurtemberg and German Empire, Manufacturer, 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 :-
My invention relates to an electric ignition apparatus with stationary armature for
gas engines. The ignition of the apparatus in gas engines by electricity has been
hitherto effected so far as magneto-electro apparatus is concerned by moving to and fro
a Siemens double T inductor suspended between the poles of fixed magnets. In
this arrangement the backward motion was usually effected by means of a lever
placed upon the axle of the inductor, which was pressed sideways by means of a
projection upon the shaft. For each ignition a deflection of ten to twenty degrees
was given, and during this a spring was compressed which drew the armature back
into its position of rest, when the projection releases the lever on the axle. The
rapid backward motion into the position of rest caused in the winding of the armature
a current jerk which was utilised for the ignition by applying the one end of the
winding to the frame of the apparatus, whilst the other insulated end was led to a
current collector, from which the current was conducted to an insulated bar. One
end of the said insulated bar projected into the interior of the cylinder, and was in
contact with the lever, which closed the current circuit, because the current Howed
from the insulated end to the current collector, and from thence to the insulated bar,
from which it passed through the lever in contact therewith into the body of the
motor, and thus into the apparatus on which the other end of the windings was secured.
In order to create a spark it was thus only necessary to interrupt the current circuit at
the proper moment which was effected by allowing the lever to strike off from the
insulated bar as quickly as possible, whereby then at the point of interruption a
powerful spark was developed. This method of ignition possesses the following
drawbacks: (1) The current must pass from the one end of the wire which lies on the
body of the apparatus or on the armature, to which it may be screwed or soldered,
through the armature and its various contact points with the apparatus itself, into
the said apparatus, and thence into the motor body, in order finally to reach the lever
applied to the insulated bar. In its course through the points of contact the current
must encounter and overcome a number of places which are lubricated. These
lubricated points, however, present a very considerable resistance to the passage of
the current, which sometimes becomes so great that the apparatus is incapable of
working. (2) For the taking off of the current a current collector is necessary
which wears out and becomes dirty, causing the same drawbacks as set forth in
paragraph 1. Moreover inexperienced persons do not understand how to handle such
Sinall parts, and it is very desirable in machines which may come into the liands of
inexperienced persons to avoid such as much as possible. (3) The comparatively
considerable weight of the armature causes a tolerably powerful blow when the
pendulum is a quick one. There is consequently created, especially in the case of
quick running machines which have a large number of ignitions per minute, & very

page_text: disagreeable noise. Moreover, the springs which are mostly employed as checks for
the reception of the blow at the backward motion are the more quickly worn the
larger the mass of the armature.
These various drawbacks are completely obviated by the apparatus of my invention.
This apparatus is characterised by having fixed in the, mechanism between the poles.
of powerful magnets a Siemens double T'inductor, around which an envelope serving
for the conduction of the magnetic lines of force is suspended and capable of motion
to and fro.
In the accompanying drawing an ignition apparatus of this kind is illustrated
and moreover.
Figure 1 shews a perpendicular section.
Figure 2a horizontal section.
The Siemens inductor is retained in this apparitus but the armature a thereof is
stationary and firmly connected by screws c with the apparatus . There can therefore
be at one end of the winding d an. inductor screwed fast to the armature, from
which the current can flow through the screws into the body of the apparatus and so
forth,, without having to pass surfaces, which, offer resistance in consequence of the
lubrication.
Between the pole shoes kk of the magnets is arranged an envelope, which is
moved to and fro in the form of a pendulum upon the stationary armature by the
controlling shaft or by other suitable means in order to conduct the magnetic lines of
force. This envelope is formed of the two discs h h fixed upon the axles ; upon
which the strips gig of soft iron coming into contact with the armature are attached.
As may be seen from this description, the weight of the movable parts, that is of the
envelope, consisting of the strips g and dises h which so to say reverses the magnetic
lines of force is reduced to a small fraction of the weight which the hitherto movable
⚫armature itself bad. This advantage is of importance in motor engines, especially
such as are employed for motor cycles, because these when formed as two cylinder
motors frequently work at an unusually high speed. According to my invention the
current collector is done away with, because the insulated end of the winding a can
be connected with an insulated terminal'e or f attached to the body of the apparatus.
The application of the pole shoe is optional. The same could even be done away
with altogether, or the magnets might themselves turn out in order to, obtain the
necessary approach or diminution of the distance between the pole shoes and the
iron strips g. The horseshoe magnets may of course be constructed of one piece, or
し
of several pieces as desired.
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:
1. The magneto-electric ignition apparatus for gas engines characterised by the use
of a stationary armature a placed between the poles of one or more powerful
magnets, around which an envelope g suitably actuated is. suspended and moves
to and fro.
2. The improved ignition apparatus for gas engines, substantially, as described with
reference to the accompanying drawings.
1000