AN IMPROVED ELECTRIC MOTOR
Year: 1879

page_text: PROVISIONAL SPECIFICATION left by Thomas James Smith at the Office
of the Commissioners of Patents on the 24th November 1879. (A com-
munication from abroad by Hippolyte Chameroy, Manufacturer, of Paris,
France)
THOMAS JAMES SMITH, of the Firm of Robertson, Brooman, and Company,
of 166, Fleet Street, in the City of London, Patent Agents. "AN IMPROVED
ELECTRIC MOTOR." (A communication from abroad by Hippolyte Chameroy,
Manufacturer, of Paris, France.)
The object of this Invention is to utilize in a special manner, hereinafter described,
the magnetic action acquired by an electro-magnet, or of a bobbin having an electric
current passed through it, to displace by its attraction a rod or bar placed inside it
or in its neighbourhood or field, and to transform this alternate to and fro move-
ment into a continuous rotary motion; an electric motor is thus obtained.
In order that the displacement of the rod or bar shall be sufficiently pronounced,
instead of only one rod being placed in the interior of the solenoid, several armatures
are arranged in it. These armatures have articulated joints arranged in zig-zag
order which allows them to extend or develope and successively approch each other,
this movement causing the alternate motion of the motor rod. A multiplication
of the displacement of the armatures is thus obtained, this being the distinctive
feature of this electro-motor.
This may be effected by various arrangements, some of which will now be
described.
According to one method the plates are joined to each other by bronze hinges,
the maximum of the separation of the armatures being limited by screws with their
heads free to move in sunken holes of convenient shape. The plates have a rod
passing through their centres from which they are insulated by suitable washers
which allow a certain play.
If an electric current is passed through the bobbin all the armatures being under
the influence of the current are magnetized, and instantly tend to approch or
attract each other; but as the top plate is fixed to the upper disc of the bobbin it
attracts to it the next armature, which in its turn attracts the next, and so on.
The upper armature causes the centre rod to descend by pressing on its upper
shoulder.
The displacement imparted to this rod is equal in amount to the distances
separating the armature plates. As the armatures only come in contact at their
ends there is no reason to fear the effects of the residual magnetism.
The movement of the centre rod is converted into a rotary motion by attaching
it to a connecting rod in connection with a crank or crank shaft.

page_text: The motor may be also advantageously arranged by constructing it with two
bobbins, two rods, two connecting rods, one shaft having two cranks, and a fly
wheel with a view of obtaining a constant motion.
The electric current is distributed alternately to one and to the other of the
two bobbins by means of a distributer or commutator fixed to a shaft.
According to another arrangement of the armatures they are joined at each end
by small plates and pivot around pins; these articulated joint plates serve as
hinges.
Instead of the solenoid surrounding the whole of the armatures, it may form
part of these, and be divided into as many small bobbins as there are armatures.
The same wire is wound around the armatures in a direction suitable for the
successive attraction of the armatures one above the other. The hinges may also be
displaced parallel to each other.
In a motor constructed according to this Invention the bobbin or solenoid
displaces itself, ascending outside the armatures and producing the attraction of
these successively.
The armatures rest at their lower part on a soft iron bar fixed to the base
of the machine.
The bobbin is connected by rods to eccentrics fixed to the shaft.
At the beginning of the stroke before the current passes through the bobbin the
latter has descended, the magnetic action is produced first on the soft iron bar
which attracts the first armature, but at the same time the bobbin has ascended by
the action of the eccentrics, and the said armature has attracted the next armature.
The action continues in this way until the bobbin arrives at the upper part of
its course.
The bobbin ascends with the same speed as the armatures descend attracted by
the soft iron bar.
If necessary pieces of iron of any size may be introduced into the bobbins to
obtain any desired magnetic power.
It is advantageous to combine two apparatus acting in contrary directions and
with alternate currents, so as to obtain more power and a more regular motion.
According to another arrangement a machine, which is preferably placed hori-
zontally, is composed of two electro-magnets fixed to the frame. In this position
the electric current passes through one electro-magnet and the first armature is
attracted; but this latter by means of its tail draws with it a sliding piece which
advances the next armature, this in its turn is attracted, and the attraction is
continued one after the other.
When all the armatures have been attracted by this electro-magnet, the current
passes through the other electro-magnet and the armatures are attracted in the
opposite direction. The sliding piece thus has an alternate movement imparted to
it, which is transmitted by means of the connecting rod and the crank to the
driving shaft.
The arrangements of this motor may be thus varied indefinitely without departing
from the nature of the Invention, and it is also understood that any source of
electricity, such as induction coils or batteries, may be employed for the working
of the motor.