Year: 1886

page_text: Date of Application, 6th Mar., 1886.
Complete Left, 6th Dec., 1886.
Complete Accepted, 28th Jan., 1887.
THOMAS ALEXANDER GARRETT 40 Scarsdale Villas Kensington London Science
Student do hereby declare the nature of this invention to be as follows:-
The invention has for its object certain improvements in dynamo electric machines
or motors.
According to my invention the armature of the machine is without coils of wire and
is formed of an inner solid cylinder capable of being magnetised and outer hollow
cylinders, each of the latter being formed by placing a number of bars capable of
being magnetised parallel to one another. Each of these bars is insulated from all the
other bars and from the inner cylinder. The cylinders are concentric and all or all
but the solid one are capable of revolving round their axes.
The hollow cylinders are
in a magnetic field most of the magnetic lines of force of which pass from the outside
to the inside or from the inside to the outside of the cylinders cutting both the
cylindrical surfaces of each cylinder, and the ends of the cylinders preferably project.
beyond the concentrated part of the magnetic field. The bars forming the hollow
cylinders are so electrically connected together outside the armature that the electro
motive forces of the seperate bars may be added together in the electric circuit of the
machine. I sometimes prefer to use only one outer cylinder in place of a number.
In the form of machine which I prefer the solid cylinder of the armature is
magnetised by the close proximity to its two ends, of the two like poles of two electro-
magnets, and the outer cylinder is closely surrounded by the other poles of these
electro magnets.

page_text: Machines or motors.
I, THOMAS ALEXANDER GARRETT, of 40 Scarsdale Villas, Kensington, London, do
hereby declare the nature of this invention and in what manner the same is to be
perforined to be particularly described and ascertained in and by the following
Statement:
This invention has for its object certain improvements in dynamo-electric machines
or motors.
According to my invention, the armature of the machine is without coils of wire
and is formed of an inner solid cylinder capable of being magnetised and outer hollow
cylinders, each of the latter being formed by placing a number of bars capable of
being magnetised parallel to one another. Each of these bars is insulated from all the
other bars and from the inner cylinder. The cylinders are concentric and all or all
but the solid one are capable of revolving round their axes. The hollow cylinders are
in a magnetic field most of the magnetic lines of force of which pass from the outside
to the inside or from the inside to the outside of the cylinders, cutting both the
cylindrical surfaces of each cylinder, and the ends of the cylinders preferably project
beyond the concentrated part of the magnetic field. The bars forming the hollow
cylinders are so electrically connected together outside the armature that the electro-
motive forces of the separate bars may be added together in the electric circuit of the
machine.
I sometimes prefer to use only one outer hollow cylinder in place of a number.
In the form of machine which I prefer, the solid cylinder of the arinature is
magnetised by the close proximity to its two ends, of the two like poles of two electro-
naguets; and the outer cylinder is closely surrounded by the other poles of these
electro-magnets.
Fig. 1 of the accompanying drawings is a longitudinal section and Fig. 2 is a
transverse section shewing diagrammatically one form of machine according to my
invention. N N and SS are electromagnetic opposite pole pieces connected together
by iron bars B and excited by coils of insulated wire, in addition to which there
might be also coils on the bars B. On a central spindle D is fixed a cylindrical
boss E which may be of iron, and on this boss is fixed the cylindrical shell consisting
of separate iron bars a and d which are electrically insulated from one another and
from E. On the opposite ends of the bars d are fixed non magnetic metal rings g
and h in electrical contact with the bars d but insulated from the bars a. Two similar
rings e and are fixed in contact with the bars a but insulated from the bars d and
also from the rings y and h. Brushes, rubbers or other current collectors are applied
to the rings e, y, h and 1. The collector on is metallically connected to that on
and the collectors on e and h have leads to the electrodes of the machine.
Instead of using a single cylindrical shell made up of two separate sets a and d of
segments or bars as described above, two concentric cylindrical shells may be
employed as shewn diagrammatically in Figs. 3 and 4 which represent respectively a
longitudinal and a transverse section of a machine so modified. In these figures the

page_text: parts corresponding with those shewn in Figs. 1 and 2 are marked by similar letters.
In this construction a is the inner and the outer of the two concentric cylindrical
shells which are made of iron insulated from each other and from the central boss E.
The rings e and are fixed on the opposite ends of the cylinder a insulated from d and
the rings g h are fixed on d insulated from a and from e and . As in the machine
first described the collector on g communicates with that on and the collectors on y
and are connected to the electrodes.
.
By the arrangement of the poles N and S as described in relation to the bars or
cylinders a and d, lines of magnetic force pass radially through the cylindrical shell
armature either from within outwards or conversely, and electrical currents pass
longitudinally along the armature. By dividing the armature either into separate bars
constituting one shell as shewn in Figs. 1 and 2, or by employing several concentric
shells as shewn in Figs. 3 and 4, electrical currents can be generated in or applied to
the separate parts of the armature either in series or in parallel circuit.
Having now particularly described and ascertained the nature of my said invention
and in what manner the same is to be performed I declare that what I claim is ―
A dynamo-electric machine or motor wherein a magnetic and conducting arinature
in the form of a cylindrical shell revolves in a magnetic field so arranged that lines of
magnetic force pass radially through the shell and electrical currents pass longitu-
dinally along it, substantially as herein described.
ADEL & IMRAI,
Agents for the Applicant.