IMPROVEMENTS IN THE CONSTRUCTION OF ELECTRO-MAGNETIC MACHINES AS MOTORS, AND IN THE CONSTRUCTION AND MODE OF EXCITING BATTERIES, AND IN THE APPLICATION OF SUCH MOTORS AND BATTERIES TO VARIOUS USEFUL PURPOSES
Year: 1869

page_text: LETTERS PATENT to Thomas Slater, of 136, Euston Road, in the Parish
of St. Pancras, and County of Middlesex, Optician, for the In-
vention of "IMPROVEMENTS IN THE CONSTRUCTION OF ELECTRO-MAGNETIC
MACHINES AS MOTORS, AND IN THE CONSTRUCTION AND MODE OF EXCITING
BATTERIES, AND IN THE APPLICATION OF SUCH MOTORS AND BATTERIES TO
VARIOUS USEFUL PURPOSES."
Sealed the 4th February 1870, and dated the 3rd September 1869.
COMPLETE SPECIFICATION filed by the said Thomas Slater at the
Office of the Commissioners of Patents, with his Petition and
Declaration, on the 3rd September 1869, pursuant to the 9th
Section of the Patent Law Amendment Act, 1852.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, THOMAS
SLATER, of 136, Euston Road, in the Parish of St. Pancras, and County
of Middlesex, Optician, send greeting.
WHEREAS I am in possession of an Invention for "IMPROVEMENTS IN
THE CONSTRUCTION OF ELECTRO-MAGNETIC MACHINES AS MOTORS, AND IN THE
CONSTRUCTION AND MODE OF EXCITING BATTERIES, AND IN THE APPLICATION OF SUCH
MOTORS AND BATTERIES TO VARIOUS USEFUL PURPOSES," and have petitioned
'

page_text: Her Majesty to grant unto me, my executors, administrators, and
assigns, Her Royal Letters Patent for the same, and have made solemn
Declaration that I am the true and first Inventor thereof.
NOW KNOW YE, that I, the said Thomas Slater, do hereby declare
that the following Complete Specification, under my hand and scal,
fully describes and ascertains the nature of the said Invention, and
in what manner the same is to be performed, in and by the following
statement, reference being had to the accompanying Drawings, and
to the letters and figures marked thereon, that is to say :-
This said Invention relates more particularly to various improvements
in the construction of electro-magnetic machines as motors, and in the
construction and mode of exciting batteries, and in the application of
such motors and batteries to various useful purposes..
These improvements consist, firstly, in the construction and arrange-
ment of electro-magnetic machines, and in transmitting of the force
obtained through these improved batteries and magnets, and rendering
such force available for useful purposes either through a reciprocating or
rotative movement.
I construct my magnet of the form shewn in Figures 1 or 2; Figure 1
is of the horse-shoe form, circular in section, but swelled out at the poles.
of the magnet at the end of each limb, so as to give a greater surface
for the armature to work on, and otherwise for the increasing of the
surface of the armature and power of the magnet. A, A, is the
magnet either made of solid wrought iron and circular in section,
or as in Figure 2 built of sections of flat soft wrought-iron plates, but
also swelled out at the poles of the magnet. I use in my machine
either one magnet as in Figure 3, or I use more than one (in a series) as
in Figure 4, increasing my surface so as to obtain a greater attractive
force for the armature to be attracted against by the "moment of
force"
alternately. B is the armature of a compound form built up. of
a series of wrought-iron plates, as shewn in section, Figures 1, 3, 4, 5.
The outer edge of the armature works on the outer edge of the poles, or
nearly so, of the magnet, and not absolutely in contact when raised
from the poles,, as shewn at C, Figures 3, 4, and 5; each end of the
armature having journals D to work on, to keep it always in its proper
position, so, that the heel of the armature may be nearly into contact at
all times with the poles when raised from the magnet. Attached to
cach of the armatures are levers E and E', to communicate the electro-

page_text: galvanic force from the armature to the connecting rods F, F", thence
to the cranks G, G', which are attached to the running shaft H, on to
which is affixed fly wheels I, so as to maintain the momentum of the
machine. There is an arrangement on the main shaft or on a separate
shaft driven by the former, on which is placed "commutators" of
metal J, J', which revolve with the shaft, and on which the conducting
wires K, K', from the battery work, or in other words are in contact;
but on these revolving discs or commutators are inserted pieces of ivory
or any non-conductor, so that as the "commutators "or discs" revolve
the force from the battery is laid on to the magnet when the armature
is raised to the angle required, and when attracted downwards the.wire
passing on to the non-conducting surface and releases the armature,
when it is raised to the position C again, and so on in succession for
any number of strokes per minute. By this repeated laying on and
taking off the force the armature B rocks up and down, the faces of the
armature coming into contact alternately with the faces or poles of the
magnet, producing the reciprocating movement as described. The
power of the machine is increased in a ratio not yet ascertained in
practice by the introduction of the compound armature, but it has been
found to be so material that I have abandoned the solid iron armature
in consequence. This compound armature will therefore form one
important element of my Invention in electro-magnetic motors.
transmitting motion to the crank shaft from the armature B through
the lever E and connecting rods F and F', it will be readily seen that
the crank is in its worst position for the transmission of dynamic force to
the rotative shaft at the time when the armature is receiving in greatest
attractive force from the magnet, but in order to obviate this difficulty
I make my connecting rods of an elastic material either of caoutchouc, or
of helical springs of steel wire, as shown in Figure 7, but supported with
extending sleeves in the inside in sections like a telescope slide, so that
when the armature closes on the magnet and the force is disconnected
the connecting rod will assume its normal length again before passing,
or at the time of passing the lower centre of the angle of 90°. The
branches of the magnet are coiled left and right with its equivalent of
insulated copper wire, so that each end of the horse-shoe may have its
opposite polarity, the ends of these wires L, L', are attached with the
negative and positive poles of my improved battery. Electro-magnetic
force in electro-magnets of this kind is due to the induction current,
which the developement and disappearance of the magnetism of an irou
In

page_text: core indicated by the insulated spiral surrounding it, which is termed
excited magnetism. Much depends also on the area of the section
and faces of the two ends of the limbs of the horse-shoe, which are
the poles. In my improved magnet I swell out the end of such limb
of the magnet at the poles, as shewn in Figures 1, 2, 3, 4 and 5, so as
to increase the surface of the poles, and also allow more attractive force
and surface for the armature to work against.
I also construct a single machine as shewn in Figure 3, where a, a,
is the frame or support of the machine, A the magnet, B the armature,
and lever E, the connecting rod F, and the fly wheel I. The "commo-
tator" or disc" for laying on and off of the fluid from the battery may
be placed on any convenient part of the machine.
Another form of working a double compound armature is shewn in
Figure 5, where the magnets A, A, are placed horizontal or nearly 'so,
and the armature B works between them, and the leverage for the
connecting rod d to transmit the power is taken off at the point e, so
that the armature would rock on the bearing or journal D. The modes
of transmitting power from these magnets by and through my com-
pound armature may be varied in their positions, and the machine in
its general conformation may be varied to suit circumstance and place,
but the main elements in my improvements in electro-magnetic
machines are in the construction and arrangement of my magnets
and compound armatures as shown in the several Figures, and fully
described in this Specification.
In regulating the action and velocity of such machines to suit
various loads I use a governor of very simple construction by placing
a small plunger "cataract" governor between the battery and the
magnet or magnets, such machine to have a valve at the bottom as the
plunger ascends to let in fluid from the small cistern, the regulator
being a valve or tap to let the water out slow or fast, as the case may
require, this will act on a small mercury bath in which the conducting
wire is immersed, the immersion being regulated by the governor as
before described which regulates the speed in proportion to the load on
the machine at the time.
In my improved battery and also improvements in the manner of
using such batteries with one or more cells, as shewn in section Figure 8,
I use excitants different from those commonly used, especially when a
uniforin current is required. As the Bunsen battery is of similar con-

page_text: struction it will be necessary here to explain the difference between my
improved battery and that of the former. Instead of using zincs in the
outer cells and carbon in the inner cells, I use soft iron plates or
cylinders in the outer cells in combination with my improved method
of exciting such metals as described, at the same time I use the carbon
in the inner cells, but with a difference also in my exciting solution
as described. The excitant I prefer is a saturated solution of nitrate of
soda or nitrate of potash. The former is found best and cheapest. In
this solution the plates of iron (if a battery of flat plates), or cylinder
of iron (if for cylindrical cells), are placed in the outer solution as in
section Figure 8. Then the carbon or graphite g is placed inside the
porous cell h which cell contains nitrous acid of the specific gravity
of 1.60 or any weaker fluid containing in solution nitrous or nitric acid,
but the stronger acid is preferable. The acid in the porous cells h,
should be about one inch higher than the solution in the outer cells
in which the iron cylinders are placed. The infiltration or "exos
or endosmosis" process through the porous tubes or cells h keeps the
outer solution containing nitrate of soda constantly supplied with acid,
preventing it from becoming alkaline. When the iron and carbon are
properly excited in their cells, the constant action of the battery can
be maintained by adding about one-sixth to one-third of fresh nitric or
nitrous acid daily. This partly exhausted acid solution I mix with the
nitrate of soda and use it for exciting the iron in the outer cells, adding
a small quantity daily in accordance with the amount of work done.
Another method of compounding a useful excitant is by using nitrous
and muriatic acids, the former of the specific gravity of 1·60, and the
latter about 1-200 in equal proportions (by measure) to be used in the
carbon cells, and the nitrate of soda as before described in the outer
cells. Or a very powerful current is generated when nitric or nitrous
acids are used alone or combined with sulphuric or muriatic acids in
small proportions in the cells with the carbon, and dilute nitric acid is
used in the outer cell with the iron. When the nitrate salts are not
used I prefer using nitric acid in the outer cells, the filtration through
the porous cells will keep the outer excitants for the iron nearly uniform
in strength until the iron solution is almost of a pasty consistancy.
Where great intensity is required in batteries, especially for telegraphic
purposes, I use the saturated solution of nitrate of soda or potash only,
both inside and outside of the porous cells. Furthermore, if an increase

page_text: of power is required without adding to the number of cells in the
process of working in any especial case, then I add to the nitrate of
soda solution in the porous cells about one-tenth part of weak acetic
acid or common vinegar.
Having now described and particularly ascertained the nature of the
said Invention, and the manner in which the same is or may be used or
carried into effect I wish it to be understood that I do not confine myself
to the precise details or general arrangements herein set forth as long as
I adhere to the main elements of these improvements as they may be
varied to suit circumstance I would have it understood that what I 1
claim is, substantially the arrangements and methods of working or
operating as herein set forth, and is,―
Firstly. The construction of electro-magnetic machines with my
improved magnets and compound armatures as fully described.
Secondly. My improvements in the construction and mode of using
and exciting batteries as fully described.
In witness whereof, I, the said Thomas Slater, have hereunto set my
hand and seal, this 2nd day of September, 1869.
Witnessed by,
PAUL R. HODGE,
THOS. W. WILLIAMS.
THOS. SLATER. (L.S.)