In- PROVEMENTS IN MAGNETO-ELECTRIC AND ELECTRO-MAGNETIC MACHINES
Year: 1857

page_text: LETTERS PATENT to Frederick Hall Holmes, of Blackwall, in the
County of Middlesex, Analytical Chemist, for the Invention of "In-
PROVEMENTS IN MAGNETO-ELECTRIC AND ELECTRO-MAGNETIC MACHINES."
Sealed the 5th January 1858, and dated the 20th July 1857.
PROVISIONAL SPECIFICATION left by the said Frederick Hall Holmes
at the Office of the Commissioners of Patents, with his Petition, on the
20th July 1857.
I, FREDERICK HALL HOLMES, of Blackwall, in the County of Middlesex,
Analytical Chemist, do hereby declare the nature of the said Invention for
"IMPROVEMENTS IN MAGNETO-ELECTRIC AND ELECTRO-MAGNETIC MACHINES," to be
as follows:-
The first part of these improvements consists in making the helices of
magneto-electric machines with moveable iron cores, which cores can be with-
drawn and replaced with facility.
The second part of these improvements relates to the commutator or break
employed in these machines, and consists in making the divisions curved, or
indented, or in broken lines, in such a manner that each roller on passing
over any one of the divisions is always in contact with the commutator, whilst
at the same time the curved or indented spaces between the divided portions
of the commutators are made sufficiently wide to prevent dust or other foreign
substance lodging therein, and thereby forming a conducting medium between
those parts that are required to be insultated the one from the other.

page_text: The third part of these improvements relates to obtaining what I call
"a compound current" from a magneto-electric machine, and consists in
arranging the helices with regard to the poles of the magnets, and the com-
mutators with regard to each other, in such a manner that out of two or
more interrupted currents of electricity, one or more constant and unin-
terrupted "compound currents are produced.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Frederick Hall Holmes in the Great Seal Patent Office on
the 20th January 1858.
.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, FREDERICK
HALE HOLMES, of Blackwall, in the County of Middlesex, Analytical Chemist,
send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Twentieth day of July, in the year of our Lord
One thousand eight hundred and fifty-seven, in the twenty-first year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto me, the
säid Frederick Hale Holmes, Her special license that I, the said Frederick
Hale Holmes, my executors, administrators, and assigns, or such others as I,
the said Frederick Hale Holmes, my executors, administrators, or assigns,
should at any time agree with, and no others, from time to time and at
all times thereafter during the term therein expressed, should and lawfully
might make, use, exercise, and vend, within the United Kingdom of Great
Britain and Ireland, the Channel Islands, and Isle of Man, an Invention
for "IMPROVEMENTS IN MAGNETO-ELECTRIC AND ELECTRO-MAGNETIC MACHINES,"
upon the condition (amongst others) that I, the said Frederick Hale Holmes,
by an instrument in writing under my hand and seal, should particularly
describe and ascertain the nature of the said Invention, and in what manner
the same was to be performed, and cause the same to be filed in the Great
Seal Patent Office within six calendar months next and immediately after the
date of the said Letters Patent.
"
NOW KNOW YE, that I, the said Frederick Hale Holmes, do hereby
declare the nature of my said Invention, and in what manner the same is
to be performed, to be particularly described and ascertained 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 :-
My said Invention relates to a peculiar construction and arrangement of

page_text: Lue nelices and commutators or breaks or magneto-electric machines, and
consists,―
Firstly, in making the helices of magneto-electric machines with movable
iron cores, which cores can be withdrawn and replaced with facility.
Secondly, in making the divisions of the commutator or break employed in
these machines of a curved or indented form, or in broken lines, so that each
of the contact rollers, in passing over any one of the divisions so formed, is
always in contact with the commutator, whilst at the same time the curved
or indented spaces between the divided portions of the commutator are made
sufficiently wide to prevent dust or other foreign substances lodging per-
manently therein, and thereby forming a conducting medium between those
parts that are required to be insulated from each other.
"
The third part of this Invention relates to a mode of obtaining what I call
"compound current from a magneto-electric machine, and consists in
arranging the helices with regard to the poles of the magnets, and the com-
mutators with regard to each other, in such a manner that out of two or more
interrupted currents of electricity, one or more constant and uninterrupted or
"compound" currents are produced.
And in order that my said Invention may be fully understood, I shall now
proceed more particularly to describe the same, and for that purpose I shall
refer to the several Figures on the Sheet of Drawings hereunto annexed, the
same letters of reference indicating corresponding parts throughout all the
corresponding Figures.
Figure 1 of the accompanying Sheet of Drawings represents a longitudinal
section of my improved helix. A is the thin iron tube, and B the wire which.
is coiled round it. Inside the tube A, I place a core C, of soft iron, which is
secured in its place by being screwed at one end c into one of the two face
plates D of the helix, the other end of the core being formed with a projecting
shoulder or collar d for the purpose of tightening itself, and of binding or
holding the face plates tight against the ends of the coil when the core is
screwed up. To facilitate the screwing or unscrewing of the core when it is
required to be introduced or withdrawn, two cavities or notches may be made
in one end, as shewn in the Drawing, for the introduction of a suitable key.
It is thus obvious that the core can be easily removed without deranging the
helix. Figure 2 represents a side elevation of my improved commutator or
break; Figure 3 is a plan of the same corresponding; and Figure 4 is a full-
sized plan of a portion of the periphery of another form of commutator, in
which the divisions are curved, shewing the peculiar indented or curved form
of the divisions between the two halves of the commutator. The insulations

page_text: in these commutators are colored red in the Drawing. A and B are the two
halves of one commutator, and it will be observed on referring to the Drawing
that the divisions in the periphery of the commutator are so formed that the
rollers C in passing over any one of them cannot descend into the intervening
space, since the opposite sides of the divisions are in the same line, as is!
shewn by the dotted line 1, 2, in Figures 3 and 4. A sufficient space is left
nevertheless in each division to prevent contact being established between the
parts requiring to be insulated by the accidental lodgment therein of dirt or
other foreign matter. I may here remark, that although I prefer using the
peculiar form of projecting parts of the commutator shewn in Figures 2 and
8, I do not confine or restrict myself to that peculiar shape, but reserve to
myself the right of using any other form wherein the same objects are attained,
namely, the obtainment of spaces sufficiently wide to prevent clogging, whilst
at the same time the rollers are prevented from descending into such spaces,
and so receiving a jumping motion as they pass successively over the several-
divisions.
Figure 4 represents a full-sized plan of three projections of a curved form
in place of being stepped as in Figure 3, but in whatever form these-pro-
jections are made they must always be-so constructed that à line 1, 2, drawn
parallel with the axis of the commutator, shall cut the two opposite sides of
the division.
_The divisions, if found desirable, may be made straight, but in place of
being disposed parallel to the axis, they should be arranged in a diagonal-
direction across the width of the commutator, so that the rollers will pass
over one end of each division before they reach the other end, and will thereby
bo prevented from descending into tho intervening spaces between the
projections.
Commutators of the description above referred to, and illustrated by the
Drawings, may obviously be used either for the purpose of directing the two
opposite currents of a magneto-electric machine in such a manner that on
leaving the commutator they shall always flow in one direction, or these com-
mutators may be employed for diverting the current of a galvanic battery in
different directions, as for example, through a number of wires coiled round
soft iron, and used in electro-magnetic engines or in telegraphic apparatus.
As the means of connecting the conducting wires with the commutator is
old and well understood by practical men, I have not considered it requisite
to illustrate it, or make any further reference thereto.
In carrying out the third portion of my Invention, I arrange the poles of
the magnets in a circle and at equal distances asunder, and dispose the helices

page_text: in a similar manner, but the number of the helices should always be a multiple
of the number of poles of the magnets.
I employ also a soparate and distinct commutator for each series of helices,
that is to say, supposing the number of helices to be double the number of
poles, I employ two commutators arranged in such a manner that the rollers
shall pass over the divisions in each commutator at the instant when the
whole of the helices in communication with such commutator are on the
"dead point" of the current, that is to say, at the instant when the current
is about to flow through the series of helices in an opposite direction. As there
are twice as many helices as poles, it follows that when one series are on the
dead point, the other series will be in the condition of maximum electric
force.
Thus by the arrangement of commutators, and series of helices corresponding
with them, as herein-before described, each commutator will alternately give
off a current which may be thus expressed for two commutators :-
First commutator.-Zero; current commencing; maximum current de-
creasing; and finally, zero.
Second commutator.-Current at maximum; current decreasing; zero;
current commencing again; and current at maximum.
Therefore, by connecting the two conducting wires of one commutator with
the two corresponding conductors of the other commutator (in cases where
quantity is required), or by connecting the positive conductor of one with the
negative conductor of the other, a compound current will be the result,
which has no dead point, and varies only from the maximum of current of
half the number of helices to the mean of the current of the whole of the
helices. A compound current of this description, produced from a double
series of helices and two commutators, will be found most advantageous in
the production of the electric light.
Having now described and particularly ascertained the nature of my said
Invention, and the manner in which the same is or may be used or carried
into effect, I would observe, in conclusion, that I do not confine or restrict
myself to the precise details or arrangements which I have had occasion to
describe or refer to, as many variations may be made therefrom without
deviating from the principles or main features of my said Invention; nor do
I claim any of the mechanical elements of which the said apparatus and parts
of apparatus are respectively composed, as being, separately or apart from the
use or application of such elements to form the combinations constituting such
apparatus and parts of apparatus respectively, as being any part of my
Invention. But what I consider to be novel and original, and therefore
said

page_text: claim as the Invention secured to me by the herein-before in part recited
Letters Patent, is,-
First, the general construction, arrangement, and combination of magneto-
electric and electro-magnetic apparatus, as hercin-before described.
Second, the application and use of helices having moveable soft iron cores, !
constructed and arranged in the manner herein-before described.
Third, the application and use of commutators or breaks, wherein the
divisions or spaces are so formed as to prevent the rollers from descending
into them, whilst at the same time they are sufficiently wide to prevent the
injurious lodgment therein of dirt or other foreign matter.
Fourth, the peculiar disposition of helices and commutators with regard to
the poles of the magnets, whereby a compound uninterrupted current is pro-
duced in one direction, as herein-before described.
In witness whereof, I, the said Frederick Hale Holmes, have hereunto
set my hand and seal, this Nineteenth day of January, One thousand 1
eight hundred and fifty-eight.