Improvements relating to Electric Tramways and Railways on the Sectional Conductor System.
Year: 1897

page_text: Date of Application, 13th Mar., 1897-Accepted, 23rd Oct., 1897
[Communicated from abroad by RICCARDO ARNO and ARISTIDE CARAMAGNA, both of
Turin, in the Kingdom of Italy, Engineers.]
Improvements relating to Electric Tramways and Railways on the
Sectional Conductor System.
I, HENRY HARRIS LAKE, of the Firm of Haseltine, Lake & Co., Patent Agents,
45 Southampton Buildings, in the County of Middlesex, 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 relates to a two-pole box for underground and electromagnetic
contacts for use in electric railways and tramways with sectional conductors.
The box is represented in various constructional forms in the accompanying
drawing, the figures of which are hereinafter referred to. The said box comprises
the following parts
(1) Two magnetic pole-pieces A A, K K are so constructed as to join an armature,
movably arranged in their interior, without the movability of said armature being
impeded; these pole pieces are, by interposition of a layer of diamagnetic material I I
so connected through the medium of conducting diamagnetic bolts, that the magnetic
pole pieces are magnetically insulated from one another but electrically connected;
(2) Au armature, arranged between the two pole-pieces A A, K K and electrically
connected therewith, comprises a magnetic piece C C C C having two poles and
being pivotally arranged on the shaft or axis O and limited by pole faces which are
similar to those of the pole pieces of the box and consist of cylinder segments arranged
symmetrically relatively to the rotary axis, the generatrices of which segments are
parallel relatively to the rotary axis, whilst its directrices, form arcs of circles having
their concave sides turned toward the rotary axis. The tangents of these directrices,
at all points with the lines perpendicular to radius vectors extending from 0, form
optionally small angles, differing however from zero. This is accomplished by
arranging the centres of curvature 010" of the directrices of the pole pieces at a
certain distance from O.
(3) A contact inaker of any kind is operated by the armature C C₁₁ and is designed
to establish the electrical connection between the box AA K K and the branch of the
line conductor as soon as the armature C C C C¹ is attracted.
During the passage of the carriage it happens that the two parts A A K K of the
box are polarized, which takes place by the action of the magnetic field produced by
the carriage itself. Then the armature CCC101 is drawn against the poles A A
and K K and the contact maker operated by the armature establishes the electrical
connection between the branch of the cable and the box A A K K and therefore
between Z and the electromotor or electromotors driving the carriage.
The contact box described in its general outlines presents the following features:
(1) As a two-pole contact box it may advantageously be included in a closed
magnetic circuit.
(2) The contact box is closed water-tight, and the joint is obtained by including a
diamagnetic material between the two magnetic pole pieces, by the connection of
which the box is constituted.

page_text: (3) The two pole armature which is under the action of the pole pieces of the
contact box does not itself establish the contact, but operates the contact maker
indirectly, therefore the contact is obtained without direct mutual contact of the pole
faces of the armature and the pole pieces of the contact box.
(4) Owing to the form of the special arrangement of the two pole magnetic armature
it happens that, although the air gap is decreased when the armature is attracted,
the points of the pole faces describe paths the length of which considerably exceeds
the width of the air gap, so that with pole faces of any extent and with an optionally
small width of the air gap in the position of rest of the arinature a greater turning
movement of this armature and therefore of the contact maker operated by the same
will be rendered possible.
(5) By the special form and arrangement of the pole pieces and of the armatures
enclosed in the same and operating the contact maker great movements of the latter
are caused, the contact taking place, not at the end, but prior to the completion of
the turning movement, and gradually improving during the continuance of the saine.
By this means we render possible in a practical and reliable manner the use of contacts
of different kinds, and also of different counter forces moving back the armature to
the position of repose, as illustrated in Figures 1 to 4 representing the several
We will now proceed to describe the features
constructional forms of the invention.
characterizing the said constructional forms.
At
According to Figure 1 we fix to the armature C C¹ C¹ an arm D D¹ which consists
of a conducting and diamagnetic part D and of an iron part D. On the armature
being attracted the part Di dips into the mercury electrically connected with the
branch of the cable Z and contained in a small cup B B of insulating material.
the surface of the mercury contained in the cup B B floats a small cylindrical or
spherical carbon block P; the lower cavity A A is likewise filled with mercury
reaching into LL.
Assuming now the box to be included in a magnetic circuit in such a manner
that the two halves A A, K K will be polarized in opposite inanners, as long as no
magnetic flux takes place, C¹ C¹ floats at the surface L L of the mercury, and D¹
does not dip into the mercury in the small cup B B. As soon as the magnetic
flux sets up, the armature CC C¹ C¹ will turn about 0; C¹ C¹ and D¹ dip into the
mercury, thereby establishing the connection between A A K K and Z. On the
cessation of the magnetic action the armature, owing both to the greater weight
of C C as compared with C¹ C¹, and also to the buoyancy due to the mercury L L, is
moved back to C C¹ into the position of repose. As soon as D discontinues to dip
into the mercury the connection between A A K K and Z will be interrupted. The
small carbon block P, which floats upon the mercury contained in B B, fulfils the
part of an intermediate contact, both prior to the immersion of the arm D¹ into
the mercury and also after the issue of D¹ from the same.
According to the arrangement represented in Figure 2 the mercury contained
in B B is replaced by a block H of conducting material, for instance of carbon with
a smooth surface. In place of the arm D D¹ use is made of an elastic plate h which
during the turning movement of the armature C C C C¹ comes first in contact at a
point M with the surface of the conducting block and then slides upon the surface of
the same, thereby perfecting the contact.
The arrangement in Figure 3 differs from that in Figure 2 in that the elastic plate h
carries at its end a small carbon block H¹ the surface of which should be extremely
smooth and fit against that of the fixed block H as soon as the contact box is set in
action, which takes place prior to the complete turning movement of the
armature C C¹ C¹ in such a manner that by the continued turning movement the
spring will be pressed and the surfaces of contact will slide upon each other, which has
the effect of improving the contact.
As compared with the arrangement in Figure 3, a modification is represented in
Figure 4 which consists in employing in lieu of the inercury L L which according to
Figure 3 is contained in the lower half A A of the box, a pulling-off spring E which
has the tendency to turn the armature CC¹ C¹ in a direction which is opposite to

page_text: that in which the armature itself rotates under the action of the polarized hilves A A
and K K of the box. The arrangement shown in Figure 4 may of course also be
applied, without the use of the mercury, to the constructional forms represented
in Figures 1 and 2.
In all the constructional forins hereinbefore set forth the stop n provided at the
bottom of A A prevents a further turning movement of the armature under the
action of the attractive force exerted upon it by the pole pieces A A, K K, whilst
the stop m limits the turning movement of the arin iture in the opposite direction.
Whereas in the arrangements shown in Figures 1 to 3 the electrical connection
between the armature CCC and the contact box A A K K is established by the
mercury LL, this function is performed, in the arrangement represented in Figure 4,
by a conducting spring plate, one end of which is fixed to the armature and the
other end to the box, and which may if desired serve itself as a pull-off spring.
The described contact boxes are equally well a lapted for application to contact
points or contact blocks which project but little from the surface of the street
and also for application to sectional rails. The system may indeed be applied to
ways with two conductors and also to those in which the return takes place through
the rail.
As our contact boxes have two poles they may if desired be included in a closed
magnetic circuit. In order to close the magnetic circuit in this instance in an easy,
practical and convenient manner, we effect the said closing by the rails of the track
and by parts of the carriage which are magnetic and which are either in proximity to
the rails or come in contact therewith.
In Figures 5 to 8 we have represented a contact box support and the magnetic
connection of the contact box with the rails, which connection has for its object to
include the box on the passage of the carriage in a magnetic circuit closed by the rails
of the track.
The two halves of Figure 5 represent two very slightly differing forms of contact
box supports a ab b which are provided with the corresponding contact boxes and
which are suitable for contact blocks which project but very little from the surface of
the street.
Figure 7 is a plan view of the same contact box support, whilst Figure 6 represents
the magnetic connection of the lower part of the box with the trackrails R, this
connection being obtained by means of a layer i of insulating material.
Figure 8 shows the general arrangement of the contact box, the track rails R R
and the cable branch Z, whilst Figures 9 and 10 represent details of the connection
between the contact box and the cable branch Z.
The bridge-shaped contact box support a a b b is furnished with wide lateral
openings through which the magnetic rods S S pass, which connect the lower part of
the contact box with the rails, thereby obviating the magnetic leakage between the
said rods S S and the contact box support, although the magnetic potential of the
rods SS and that of the upper part of the contact box and therefore of the whole
contact box support differ from each other.
The contact box support is furnished above with an opening through which the
contact box is introduced, the cover of this box bearing upon the flanges of the said
opening, to which it is fixed with screws.
For enabling the contact box to be severed from the end of the cable branch
simply by removing the box itself without any further manipulations, we make use
of two bells C C¹ of insulating material (such as for example porcelain). The lower
bell C is for instance secured to the wooden block L, upon which the contact box sup-
port bears, and is furnished with a metallic core q¹ to which the cable branch Z is joined.
The upper bell C opens downwardly, is fixed to the contact box and provided with
a metallic sleeve q which is in connection with the fixed part of the contact maker.
The edges of the upper bell dip into a pasty insulating material V which is contained
in the lower bell. In the interior of the space closed by the two bells, the metallic
parts qq which are to fit one into the other with great friction, set in conducting
electrical connection.

page_text: Having now particularly described and ascertained the nature of the said invention
and in what manner the same is to be performed, as communicated to me by my
foreign correspondents, I declare that what I claim is :-
First. In electric tramways and railways having a current feed by sectional
conductors and underground electromagnetic contacts, an hermetically closed two-pole
contact box whose two parts A A, K K held strongly together constitute the two
magnetic poles and which are in conducting electric connection with each other and
are inagnetically insulated from each other, which box contains a magnetic two-pole
armature adapted to turn about a diamagnetic axis 0 and operating contact makers
of any kind, the pole faces C C C¹ C₁ of the aforesaid armature consisting of sections
of a cylinder arranged symmetrically to the rotary axis O the generatrices of the
sections being parallel to the rotary axis and the directrices of the same which have
their concave side turned towards the rotary axis being so shaped that their tangents
orm at all points with the lines perpendicular to the radius vectors extending from
the point of the rotary axis situated in the same plane, optionally small angles
deviating from naught, the points of the pole faces C C C C traversing paths which
are considerably longer than the size of the intermediate air gap despite the decrease
of this air gap due to the attraction of the armature by the pole pieces, so that, with
the said pole faces made of any desired extent and with an optionally sinall width of
the intermediate air gap in the position of repose of the armature, a greater rotary
movement of the same and of the contact maker operated thereby will be rendered
possible, whereby the contact made during the rotary movement of the armature
will be improved by the further movement to be accomplished.
Second. In electric tramways and railways having a current feed by sectional
conductors and underground electromagnetic contacts, a contact box of the kind
characterized in the first claim, the lower pole piece of which is connected by
rods S S of magnetic material with the rails R, thereby including the contact box,
on the passage of the carriage, in a magnetic circuit closed by the rails of the track.
Third. In electric tramways and railways having a current feed by sectional
conductors and underground electromagnetic contacts, a contact box of the kind
characterized by the first and second claims, which is held in a bridge shaped box
support a abb open on both sides, which admits through the two lateral openings
the magnetic rods S S connecting the lower part of the contact box with rails R of
the track, whilst an opening provided in the upper horizontal side of the box
support is designed for the reception of the contact box.
Fourth. In electric tramways and railways having a current feed by sectional
conductors and underground electromagnetic contacts, a contact box of the kind
characterized in the first, second and third claims, which joins the branch Z of the
line conductor by means of two bells C C¹ made of insulating material such as for
example porcelain and containing the connecting parts, the lower bell C' fixed to
the ground and turned upwards containing a pasty insulating material V, whilst
the upper bell C secured to the contact box has its opening turned downwards, the
edges dipping into the said insulating material, thereby facilitating the joining of
the contact box to the cable branch Z and also the removal of the same.
1
C
1007
HASELTINE, LAKE & CO.,
45 Southampton Buildings, London, W.C., Agents for the Applicant.