IMPROVEMENTS IN ELECTRICAL APPARATUS
Year: 1879

page_text: LETTERS PATENT to Edward Griffith Brewer, of 33, Chancery Lane, in the
County of Middlesex, for the Invention of "IMPROVEMENTS IN ELECTRICAL
APPARATUS." A communication from abroad by Edouard Alphonse Chambrier,
of Paris, France.
Sealed the 27th April 1880, and dated the 30th October 1879.
PROVISIONAL SPECIFICATION left by the said Edward Griffith Brewer at
the Office of the Commissioners of Patents on the 30th October 1879.
54
EDWARD GRIFFITH BREWER, of 33, Chancery Lane, in the County of Middlesex.
IMPROVEMENTS IN ELECTRICAL APPARATUS.” A communication from abroad by
Edouard Alphonse Chambrier, of Paris, France.
After much study the inventor has discovered that the greatest attractive force
of soft iron in electro magnets is not always found at the same point or at hand
(à la main distance), that is to say, that the pole varies according to the materials
employed and the kind of construction. According to this Invention the inventor
has combined a new arrangement of electro magnet, whereby the apparatus can be
regulated in such manner as to find the most favourable point for obtaining the
maximum of attractive power or force, by making an electric current pass into the
bobbins; this is a part of the Invention, but another and more important part consists
in the deformation or changing of the form of the ordinary plane surfaces of the
armature, and of the end of the bar, so as to increase the dimension of the surface
presented.
The Invention refers,―
1. To the power of regulating the surfaces in contact, so as to be able to
determine the most advantageous point to obtain the maximum effect.
2. The deformation or changing the form of the ordinary plane surfaces of the
armature, and of the end of the bar or electro magnet in order to increase the
dimension of the presenting surfaces.
The electro magnet is hollowed out internally into or over, or both of which the
armature fits.

page_text: It would be impossible to describe all the modifications of which this Invention
is susceptible, but if we take 10 as the attractive surface, say of a, it is equal to the
corresponding surface, say of d.
The following table will show the difference between the known and the new
system --
In the known system, let a=10, d=10, or a=10, d=10.
In new system, a=10, d=10+10+10, or a=10, d=30.
a=10, d=10+5+10+5+10+5+10, or a=10, d=55; these examples may be
multiplied indefinitely.
It should be noticed that in some instances the soft iron bar is hollow, and carries
a screw which can be brought nearer to or farther from another; either of these
screws may be varied until the point of contact is found which gives the greatest
attractive force; this only concerns the plane surfaces of the screws above referred
to, only outside the plane surfaces there is the influence of circular surfaces, and it
should be noticed that in most instances the surfaces of contact are much more
considerable than if they acted only on the plane surfaces; a double advantageous
result is thus obtained :-1. To determine by means of the screws the most favourable
point of contact to obtain the maximum of attractive power, every proportion being
preserved. 2. To augment the surfaces of contact, not only on the plane surfaces,
but even on the bent or circumferential surfaces.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said Edward Griffith Brewer in the Great Seal Patent Office on the
30th April 1880.
EDWARD GRIFFITH BREWER, of 33, Chancery Lane, in the County of Middlesex.
"IMPROVEMENTS IN ELECTRICAL APPARATUS." A communication from abroad by
Edouard Alphonse Chambrier, of Paris, France.
After much study the inventor has discovered that the greatest attractive force
of soft iron in electro magnets is not always found at the same point or at hand
(a la main distance), that is to say, that the pole varies according to the materials
employed and the kind of construction. According to this Invention the inventor.
has combined new arrangements of electro magnets, whereby the apparatus can be
regulated in such manner as to find the most favourable point for obtaining the
maximum of attractive power or force by making an electric current pass into the
bobbins; this is a part of the Invention, but another and more important part
consists in the deformation or changing of the form of the ordinary plane surfaces
of the armature, and of the end of the bar, so as to increase the dimension of the
surface presented.
The Invention refers:-First. To the power of regulating the surfaces in contact
so as to be able to determine the most advantageous point to obtain the maximum
effect.
Second. The deformation or changing the form of the ordinary plane surfaces of
the armature, and of the end of the bar of electro magnet, in order to increase the
dimensions of the presenting surfaces.
The electro magnet is hollowed out internally into or over, or both of which the
bar or armature fits.
It would be impossible to describe all the modifications of which this Invention
is susceptible.
The annexed Drawings, Figures 1, 2, and 3 illustrate the basis of this system, and
the difficulties there would be of representing all the combinations which could be
made. a is the electro; d, the bar in Figure 1, which represents the known mode.
If we take 10 as the attractive surface, say of a, it is equal to the corresponding
surface, say, of d.
The following table will shew the difference between the known and the new
system :-
In the known system, Figure 1, let a=10, d=10, or a=10, d=10.
In new system, Figure 2, a=10, d=10+10+10, or a=10, d=30.
Figure 3, a 10, d=10+5+10+5+10+5+10, or a=10, d=55; these examples
may be multiplied indefinitely, and at Figures 4 to 14, various illustrations of
modified forms are given.
It should be noticed that in some instances, at Figure 9 for example, that the
soft iron bar a is hollow, and carries a screw b, which can be brought nearer to or
further from another screw c; either of these screws may be varied until the point
of contact is found which gives the greatest attractive force; this only concerns the
plane surfaces of the screws above referred to, only outside the plane surfaces there
is the influence of circular surfaces, and it should be noticed that in most instances
illustrated in the Drawings that the surfaces of contact d, and those of e, are much
more considerable than if they acted only on the plane surfaces b and c; a double
advantageous result is thus obtained.
1. To determine by means of the screws b, c, the most favourable point of contact
to obtain the maximum of attractive power, every proportion being preserved.
2. To augment the surfaces of contact not only on the plane surface, but even on
the bent or circumferential surfaces.

page_text: Having now described the nature of the said Invention, and in what manner the
same is to be performed, I declare that I claim as the aforesaid improvements in
electrical apparatus,—
First. The power of regulating the surfaces in contact so as to be able to
determine the most advantageous point to obtain the maximum effect, substantially
as set forth.
Second. The deformation or changing the form of the ordinary plane surfaces of
the armature, and of the end of the bar or electro magnet, in order to increase the
dimensions of the presenting surfaces, substantially as set forth.
In witness whereof, I, the said Edward Griffith Brewer, have hereunto set my
hand and seal, this Twenty ninth day of April, in the year of our Lord
One thousand eight hundred and eighty.
E. G. BREWER. (LS.)