Improvements in Electrical Influence Machines.
Year: 1899

page_text: Improvements in Electrical Influence Machines.
I, CHARLES SELIM LEMSTRÖM, of Helsingfors, Finland, in the Empire of Russia,
Professor, do hereby declare the nature of this invention to be as follows:-
-
This invention has for its object an improvement in electrical machines of the
class in which the effective surfaces are in the form of two cylinders or drums
of glass or other non-conducting material, one of which cylinders is arranged
inside the other, whilst both are so mounted that they may be set in rotation
in opposite directions by a common shaft.
This improved influence machine characterises itself from similar machines
hitherto known, in that electricity is taken, not only from the outer drum but also
from the inner one. Only in the newest machine of Wimshurst (see Engineer-
ing, year 1888, Vol. 1, page 423) with a vertical axis is electricity collected from
both drums by two pairs of combs or brushes which are mounted on a common
insulated support at the upper ends of the drums. This arrangement however
does not allow of the machine being made of large dimensions, because in such
an arrangement the insulation cannot be maintained.
The improved machine which forms the object of the present invention may,
on the contrary, be made in any suitable size, and complete insulation be easily
obtained. This is rendered possible by the supporting spindle on which the two
drums are mounted being formed at the ends of metal and carried by insulated
metallic supports whilst the centre part of this supporting spindle is formed of
non-conducting material which insulates the metallic ends one from the other.
These carry each two combs, one of them arranged inside and the other outside the
cylinder in such a way that these combs stand opposite one another. The conduct-
ing ends of the supporting spindle and their supports form the poles of the machine
from which electricity can be taken.
The machine is arranged on a foundation or bed plate carried by an under frame
consisting of two metallic supports fixed on a common foundation or bed plate.
A shaft carrying three belt or cord pulleys is mounted in the centre bars of the.
said supports or framework, one of said pulleys serving for driving the machine
from a suitable source of power, whilst the other two pulleys set in rotation the
drums arranged above the said shaft and above the upper base plate. A handle
or hand crank provided on this shaft may be utilised for operating the machine
by hand.
Two posts which carry the fixed supporting spindle of the two drums are
arranged on the upper plate near its ends. The lower part of these posts consists
of wood, and the upper part of a strong ebonite cylinder of at least five centi-
metres in height. These cylinders carry metallic balls which are perforated and
receive the ends of the carrying spindle without allowing the same to rotate.
The ends of this spindle are formed of metal, for instance steel. The centre is
formed of a thick cylindrical piece of ebonite. The larger of the hollow drums.
or cylinders gives the measure for all the other parts of the apparatus and for its

page_text: capabilities of delivery or effectiveness. The drums are made of glass or other
suitable insulating material and so arranged that the edges of the outer drum
project at least 11 centimetres beyond those of the inner drum. Between the
inner surface of the outer cylinder and the outer surface of the inner cylinder
there is an interstice of 1-4 mm. The drums are preferably coated with metal
pieces consisting of strips about 5 mm. in width of thin tin foil or plates on
which three semi-cylindrical metal pieces provided with rounded ends which may
be formed of tin sheets of about 1 mm. in thickness are fixed. These meial strips
are preferably cemented on the outer surface of the outer drum and on the inner
surface of the inner drum parallel with the axis of the drums, whilst the distance
of the ends of the strips from the ends of the drum is 4-5 m/m and the distance
of these metal strips from one another may be selected according to the size of the
drums. The cylindrical drums are carried on ends or bottom pieces. These may
be formed of a perforated ebonite disc but in large machines of a central ebonite
disc of at least six centimetres in size carrying radial arms formed of several
layers of walnut or mahogany wood glued one upon the other and having their
grain crossing and which terminate in curved pieces or segments formed of
ebonite which rest against the cylinder. The arms in this bottom or end are
formed in the shape of propellers so that they draw in air on one side and expel
it on the other side. This draught of air causes the air in the machine to be
constantly changed and therefore a condition in which the air is charged suffi-
ciently to endanger the insulation cannot arise, whilst at the same time any
deposition of moisture in the machine is prevented and any moisture deposited in
the machine when it is stationary is removed. In the Wimhurst machine the
drums have the ends closed below but no ends at the top so that the change of
the air contained in the drum can only take place very slowly. In the centre of
the ebonite naves of the inner drum suitable bearing bushes are inserted to bear
on the fixed spindle whilst in the naves of the outer drum similar bearing bushes
are inserted, one of which is suitably fitted over one of the other bushes, whilst the
other bush is directly mounted on the pin or journal of the carrying spindle. A belt
or cord pulley is firmly connected with one bush of the outer drum, and a belt
or cord pulley with one bush of the inner drum. These pulleys may be set in
rotation by means of a cord or belt from the cord or belt pulleys on the driving
shaft. One of the cords is crossed, the other straight, so that, on the shaft being
rotated, the two drums are set in rotation in opposite directions.
In contrast to the machines hitherto known, no weight is attached by the
applicant to the inner drum being airtightly enclosed by the outer one.
Each hollow drum is provided with a transverse conductor, the inner one being
preerably set at about 90° to the outer one. These transverse conductors carry
at each end at least three brushes of fine copper wires such as are employed for
embroideries. These brushes encounter the thickened part of the metal coverings
of the drums and are mounted in crossbars of metal. In the outer transverse
conductor these crossbars are carried by a curved metal piece. In the inner
cylinder this curved metal piece is replaced by a cross piece of ebonite traversed
by a thick metal wire which is mounted on the ebonite pieces of the fixed spindle.
The arrangement for collecting the electricity consists of two pairs of metallic
collecting combs. each of which is carried by one of the metallic ends of the
spindle. Of the two collecting combs of each pair, one is arranged outside and
one inside the drums, and both are opposite one another. The length of these
collecting combs corresponds preferably to that of the metal coverings of the
drums. The ends of the collecting combs must thus also remain about 4 centi-
metres distant from the ends of the drums. The discharging rods are also ordinary
ones and are connected with the posts of the carrying spindle, the ends of which.
form the poles of the machine.
The machine is surrounded externally by a case partly formed of glass which
fits closely to the upper frame and has a lid which may be shut so that air is
excluded from the case. In order to keep the-air in the case dry, it is connected,

page_text: with a small drying apparatus. This consists of a sheet metal container in which
a petroleum lamp may be inserted, which lamp is so arranged that when burning
it draws the necessary air out of the container. The latter is connected by means
of a sheet metal pipe with the under part of the case. Above the draught-glass
of the lamp there is mounted a second container formed of sheet copper which is
provided with two divergent tubular projections in which upwardly bent glass
tubes, filled with phosphoric anhydride or any suitable hygroscopic material, are
inserted. This copper container is connected by means of a pipe with the case,
When the petroleum lamp burns, air is drawn out of the case and as the copper
container is simultaneously warmed dried air penetrates into the case.
When the machine is to be set in operation, the drying apparatus is started first
by lighting the petroleum lamp whereby the air in the case is dried. It is
sufficient then to set the shaft in rotation by hand or by means of mechanical
power. The excitement takes place automatically in consequence of the use of the
covering strips and cross conductor brushes, the latter producing some frictional
electricity which is sufficient to initiate the influence action. The electricity
developed in the ordinary way may be collected from the poles of the machine in
any suitable manner.
By this machine a considerably greater quantity of electricity is delivered per
revolution than with the influence machines of Holz and Wimshurst and also than
that of Gläser. For these results the drying of the air contained in the machine
and the current of air produced by the propeller shaft ends of the machine are very
essential.
Dated this 4th Jox of Fale 1900
WM. P. THOMPSON & Co.,
Of 6, Lord Street, Liverpool, Agents for the Applicant.
Improvements in Electrical Influence Machines.
I, CHARLES SELIM LEMSTRÖM, of Helsingfors, Finland, in the Empire of Russia,
Professor, do hereby declare the nature of this invention and in what manner the
same is to be performed, to be particularly described and ascertained in and by
the following statement:-
This invention has for its object an improvement in electrical machines of the
class in which the effective surfaces are in the form of two cylinders or drums
of glass or other non-conducting material, one of which cylinders is arranged
inside the other, whilst both are so mounted that they may be set in rotation
in opposite directions by a common shaft.
This improved influence machine differs from similar machines hitherto known,
in that electricity is taken not only from the outer drum but also from the inner
one. Only in the newest machine of Wimshurst (see Engineering, year 1888,
Vol. 1, page 423) with a vertical axis is électricity collected from both drums
by two pairs of combs which are mounted on a common insulated support at the
upper ends of the drums. This arrangement however does not allow of the machine
being made of large dimensions, because in such an arrangement an even support
or mounting of the drums at both ends is not possible, and more particularly the
supporting of the drum ends on which the internal combs are carried to the
outside, by inserting a bottom or cross arm, is excluded on account of its encounter-
ing the conductors.
The improved machine which forms the object of the present invention may,
on the contrary, he made in any suitable size, and a good and sure mounting

page_text: of the drums at both ends is obtained. This is rendered possible by the drums being
mounted on a common fixed supporting spindle which however is only formed at
the ends of metal and is there carried by insulated metallic supports, whilst
the centre part of this supporting spindle is formed of non-conducting material
which insulates the metallic ends one from the other. These carry each two combs
one of them arranged inside and the other outside the cylinder in such a way that
these combs stand opposite one another. The conducting ends of the supporting
spindle and their supports form the poles of the machine from which electricity
can be taken.
In the accompanying drawings, Figures 1 and 2 are two views in perspective
of the machine, taken from different sides, Figure 1 showing the machine with
the drying apparatus and Figure 2 without the same; Figure 3 is a horizontal
section of the machine; Figure 4 a vertical section of the inner drum; Figure 5
a view of the metallic attachments or coverings on the drum, and Figure 6
sections of the said metallic coverings; Figure shows in an elevation partly in
section, and Figure 8 in a section on the line X Y of Figure 7, the propellor
like shape of the arms carrying the drum.
As may be seen in Figure 1, the machine is arranged on a table or bed plate B
carried by an under frame consisting of two metallic supports C fixed on a
common foundation or bed plate A. A shaft D carrying three belt or cord pulleys
is mounted in the centre bars C¹ of the said framework C, one of said pulleys
serving for driving the machine from a suitable source of power, whilst the other
two pulleys set in rotation the drums E and E' arranged above the said shaft and
above the plate B. A handle or hand crank d provided on this shaft may be
utilised for operating the machine by hand.
drums E
of these
of at least
which are
Two posts F, which carry the fixed supporting spindle G of the two
and E, are arranged on the plate B near its ends. The lower part
posts consists of wood, and the upper part of a strong ebonite cylinder
five centimetres in height. These cylinders carry metallic balls
perforated and receive the ends a of the carrying spindle G without allowing the
same to rotate. The ends a of this spindle G are formed of metal, for instance
steel. The centre is formed of a thick cylindrical piece of ebonite e. The larger
of the hollow drums or cylinders E E' gives the measure for all the other parts
of the apparatus and for its capabilities of delivery or effectiveness. The drums are
made of glass or other suitable insulating material and so arranged that the edges
of the outer drum E¹ project at least 1 centimetres beyond those of the inner
drum E. Between the inner surface of the outer cylinder and the outer surface
of the inner cylinder there is an interstice of 1-4 mni. The drums are
preferably coated with metal pieces f. Figures 5 and 6, consisting of strips about
5 mm. in width of thin tin foil or plates on which three semi-cylindrical metal
pieces provided with rounded ends which may be formed of tin sheets of about
1 mm. in thickness are fixed. These metal strips are preferably cemented on the
outer surface of the outer drum and on the inner surface of the inner drum
parallel with the axis of the drums whilst the distance of the ends
of the strips from the ends of the drums is 4-5 millimetres and
the distance of these metal strips from one another may be selected according
to the size of the drums. The cylindrical drums are carried on the ends of
bottom pieces H and H. These may be formed of a perforated ebonite dise but in
large machines of a central ebonite disc of at least six centimetres in size.
carrying radial arms formed of several layers of walnut or mahogany wood
glued one upon the other and having their grain crossing and which terminate
in curved pieces or segments jj formed of ebonite which rest against the
cylinder. The arms in this bottom or end are formed in an oblique direction
or sloping to the axis similar to screw propellors or ventilators (Figures 7 and 8)
the obliquity of the two cylinders being in opposite directions. as shown in
Figure 8, so that they draw in air on one side and expel it on the other side. This
draught of air causes the air in the machine to be constantly changed and therefore

page_text: a condition in which the air is charged sufficiently to endanger the insulation
cannot arise whilst at the same time any deposition of moisture in the machine is
prevented and any moisture deposited in the machine when it is stationary is
removed. In the Wimshurst machine the drums have the ends closed below but
no ends at the top so that the change of the air contained in the drum can only take
place very slowly. In the centre of the ebonite naves % of the inner drum E
suitable bearing bushes are inserted to bear on the fixed spindle G whilst
in the naves of the outer drum similar bearing bushes are inserted, one
of which is suitably fitted over the bush whilst the other bush is directly
mounted on the pin or journal of the carrying spindle G. A belt or cord pulley
is firmly connected with the bush and a belt or cord pulley with the bush.
These pulleys may be set in rotation by means of a cord or belt from the cord or
belt pulleys on the driving shaft 1). One of the cords is crossed, the other straight,
so that, on the shaft G being rotated, the two drums are set in rotation in opposite
directions.
1
In contrast to the machines hitherto known no weight is attached by the
applicant to the inner drum being airtightly enclosed by the outer one.
Each hollow drum is provided with a transverse conductor J J', the inner one
being preferably set at about 90° to the outer one. The outer one J is shown
in Figures 1 and 2 the inner one J in Figures 3 and 4. These transverse con-
ductors carry at each end at least three brushes m and m¹ of fine copper wires such
as are employed for embroideries. These brushes encounter the thickened part
of the metal coverings f of the drums and are mounted in crossbars and n¹ of
metal. In the outer transverse conductor J¹ these crossbars are carried by a
curved metal piece . In the inner cylinder this curved metal piece is replaced
by a cross piece o of ebonite traversed by a thick metal wire which is mounted
on the ebonite pieces e of the fixed spindle G.
The arrangement for collecting the electricity consists of two pairs of metallic
collecting combs qq each of which is carried by one of the metallic ends of
the spindle G. Of the two collecting combs of each pair, one is arranged outside
and one inside the drums, and both are opposite one another. The length of these
collecting combs corresponds preferably to that of the metal coverings of the
drums. The ends of the collecting combs q q' must thus also remain about 4 centi-
metres distant from the ends of the drums. The discharging rods are also ordinary
ones and, as shown in Figure 1, are connected with the posts of the carrying
spindle, the ends of which form the poles of the machine.
The machine is surrounded externally by a case K partly formed of glass which
fits closely to the upper frame and has a lid which may be shut so that air is
excluded from the case. In order to keep the air in the case dry, it is connected
with a small air drying apparatus.. This consists of a sheet metal container. L
in which a petroleum lamp M may be inserted, which lamp is so arranged
that when burning it draws the necessary air out of the container L. The latter
is connected by means of a sheet metal pipe N with the under part of the case K.
Above the draught-glass of the lamp there is mounted a second container Û formed
of sheet copper which is provided with two divergent tubular projections Rin
which upwardly bent glass tubes, filled with phosphoric anhydride or any suitable
hygroscopic material, are inserted. This copper container is connected by means
of a pipe S with the case K. When the petroleum lamp burns, air is drawn out
of the case and as the copper container is simultaneously warmed, dried air
penetrates into the case.
When the machine is to be set in operation, the drying apparatus is started
first by lighting the petroleum lamp, whereby the air in the case K is dried. It
is sufficient then to set the shaft D in rotation by hand or by means of mechanical
power. The excitement takes place automatically in consequence of the use of the
covering strips and cross conductor brushes, the latter producing some frictional
electricity which is sufficient to initiate the influence action. The. electricity

page_text: developed in the ordinary way may be collected from the poles of the machine in
any suitable manner.
By this machine a considerably greater quantity of electricity is delivered per
revolution than with the influence machines of Holz and Wimshurst and also than
that of Gläser. For these results the drying of the air contained in the machine
and the current of air produced by the propellor shaft ends of the machine are
very essential.
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:
1. An influence machine having two drums revoluble in opposite directions in
which electricity is accumulated both from the inner surface of the inner drum
and the outer surface of the outer drum, characterised by each of the two pairs of
combs for collecting electricity inside and outside the drums being carried by
one of the ends, which are utilised as poles, of the fixed supporting spindle of
the drums, which spindle supports both ends of the drums by means of inserted
ends or cross arms, and which spindle for this object is formed of two metal pins
or journals insulated one from the other by an inserted or intermediate block of
ebonite or the like, substantially as hereinbefore described.
2. An influence machine such as described in which the inner transverse con-
ductor is carried by the insulated intermediate piece of the drum-supporting
spindle, substantially as described.
3. An influence machine such as described, in which both the inner surface of
the inner drum and the outer surface of the outer drum are coated with projecting
rounded metallic contact pieces or coverings which are encountered by and
excited by means of wire brushes on the transverse conductors, substantially as
described.
4. The combination with an influence machine such as described, of an air
drying apparatus, characterised by the arrangement of a sheet metal container
connected by means of a pipe with a case covering the machine, said container
having a petroleum lamp which draws its air for combustion out of the said case,
and a second container connected with the upper part of the case by means of a
pipe and arranged above the draught glass of said lamp, in which second con-
tainer upwardly bent pipes filled with a suitable hygroscopic material are con-
nected substantially as described.
5. An influence machine such as described in which the cross arms in the ends
of the drums supporting the latter are formed in the shape of propellors in order
to produce a current of air passing through the drums and an uninterrupted
replacement by dried air and thereby prevent any stagnation of damp air in the
machine substantially as described.
Dated this 1st day of November 1899.
WP. THOMPSON & Co.,
Of 6, Lord Street, Liverpool, Agents for the Applicant.