Improvements in or relating to Overhead Systems for Electrical Transmission of Energy.
Year: 1899

page_text: Date of Application, 16th May, 1899
Complete Specification Left, 15th Feb., 1900-Accepted, 28th Apr., 1900
Date of Application, 16th May, 1899
Complete Specification Left, 15th Feb., 1900-Accepted, 28th Apr., 1900¯
PROVISIONAL SPECIFICATION.
Improvements in or relating to Overhead Systems for Electrical
Transmission of Energy.
I, WILLIAM ROUTLEDGE, of No. 32, Woodbine Street, South Shields, in the
County of Durham, Electrical Engineer, do hereby declare the nature of this
invention to be as follows:-
My invention relates to certain improvements in or relating to overhead
systems for electrical transmission of energy, and has for its objects the switching
off of the current instantly a wire break, before the end can touch the ground,
the current however being maintained up to the section in which the break has
occured, the broken section being alone cut off, and the action of said switch or
contact being dependent upon the tension of the conductors.
In carrying my invention into effect I. presume the system to consist of a
number of sections of overhead conductors supported by poles and feeding the
motors of the vehicle by a trolley whip or contact, the other conductor being
earthed, hence it is advisable to adopt such a safety device to prevent the end of
a broken wire touching earth until the current is switched off on both sides of
the rupture, the remaining sections being still active. In carrying my invention
into effect I preferably employ two cranked metal arms, the horizontal members
of which are longer than the vertical. These are fulcrummed to a central
plate, (properly insulated) in such a manner that the horizontal arms extend in
opposite directions and the ends of the sections of the conductor are attached
to each. The central insulated plate is pivotted above the fulcrums before
described, to the projecting carrier, or other part of the post. The shorter
vertical members of the two cranked arms are joined by a sliding switch connec-
tion, having the female portion on one side and the male portion on the other,
the connection being in contact when the horizontal arms are kept in line by
the tension of the conductor on each side, or as in the case of an end section or
terminal section, a spring or weight, or supplementary wire returned over the
section but carrying no current, may provide the requisite tension.
The manner of automatic action is as follows.
If a wire in any one section breaks, the tension is relieved on one arm of
cach switch, and the tension imposed upon the other being no longer compen-
sated, it pulls the arm upon the broken side over, the distance between the
fulcrum and central pivot forming a lever, and the switch contact is immediately
broken, the different ratios of measurement between the members of the crank
arms, and distances between fulcrums and central pivot controlling the rapid
action. The varying tensions due to changes of atmospheric temperature must
also be taken into effect in designing the switch. A central piece may be
rigidly fixed so that the contact pieces on both vertical arms may be in contact
therewith, when both wires are in tension on the horizontal arms and when a
rupture takes place the contact on the broken side is of course pulled away

page_text: from the fixed contact aforesaid. This fixed contact conveniently serves as a
"feeder" connection when any of the sections are fed from a main circuit.
I may vary the construction of the switch to suit various conditions of applica-
tion, since the essential feature of my said invention is to utilise the tension of
the conductors as a means for actuating such switches, and breaking contact on
the ruptured section only so that a "live" wire does not reach the ground or
anything contiguous thereto to the common danger.
FREDK. WALKER,
73, St. Stephen's Road, Upton Park, London, E.,
Agent for the Applicant.
Improvements in or relating to Overhead Systems for Electrical
Transmission of Energy.
I, WILLIAM ROUTLEDGE, of No. 32, Woodbine Street, South Shields, in the
County of Durham, Electrical Engineer, 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:-
My invention relates to certain improvements in or relating to overhead
systems for the electrical transmission of energy, and has for its object the switching
off of the current instantly when a conductor or wire breaks, before the end
can touch the ground, the current being maintained, up to the section in which
the break has occurred, the broken section being alone cut off, and the action
of said switch or contact being dependent upon the tension of the conductors
upon both sides.
In order that my invention may be clearly understood I have appended the
accompanying sheet of drawings, in which Figure 1 shows the device in the
closed position, and Figure 2 shows the opened circuit when a break upon one
side has occurred. Figure 3 shows a split carrier or travelling conductor applied
to this device attached to a trolley wheel or pin.
In carrying my invention into effect I presume that the transmission system
consists of a number of sections of overhead conductor supported by poles, and
Feeding the motors of the vehicle by a trolley whip or contact, the other conductor
being "earthed" or "grounded"; hence the advisability of adopting a safety
device to prevent the end of a broken wire from touching earth until the current
is switched off on both sides of the rupture, the remaining sections being still
active.
Referring to the appended drawings I preferably employ two cranked metal
arms A A, the horizontal members a a of which are longer than the vertical
members b b¹. These arms A A' are fulcrummed at f f to an insulated plate C
in such a manner that the horizontal members of the arm's A A' extend
from the fulcrums f f¹ in opposite directions, and the ends of the conductor c c
forming the terminals of two sections are attached to each. The central insu-
lated plate C is pivotted at d above the fulcrums f f to the carrying post, or a
bracket thereon.
When in tension by reason of an unbroken conductor on each side, the vertical
members b b of the cranks A A' are connected by a knife switch D, consisting
of a knife or wedge shaped end k (Figure 2) entering and making contact with a
split brush or the like 7. This contact is maintained whilst the tension of the

page_text: conductors on both sides is normal. In the case of a terminal post, the end
crank lever is kept in position by a counterweight or spring, or in some cases by
a supplementary wire carried back over the section, to provide the requisite
tension.
The automatic action of this switch is as follows, that is to say; -normally
the two vertical members b¹ maintain the electrical connection between the
conductors ce by the switch D. If c or c breaks, and the tension that maintains
the contact is relieved upon each arm A A', and the arm A' Figure 2 drops as
shown, and the contact at D is broken before the ruptured wire can touch the
earth, owing to the position of the fulcrums f f below the pivot d of the insulated
plate C the distance between these causing C to act as a lever. The rapid action
which breaks the circuit at D is due to the ratio of the several fulcrums and
pivots, and renders the broken conductor "dead" before the end can touch the
ground. The varying tensions due to atmospheric changes of temperature must
be allowed in designing the switch, since the range between contact and break
is small. I may vary the construction of the switch to suit various conditions
of application, always preserving the essential features thereof.
Referring to Figure 3, a sheet metal conducting slip F is fixed to the trolley
wheel T carried by the whip W which is attached to the vehicle, said slip F
serving to bridge the arms A A' when in tension.
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:-
"
:
First. In an overhead system for the electrical transmission of power in which
cne conductor is carried from post to post and the other conductor earthed
or grounded" the method of and means for rendering a broken section neutral
before reaching the ground substantially as herein described and shown by the
drawings.
Second. In an overhead system for the transmission of electrical energy as
referred to in the preceding claim, the employment of two arms A A¹ carrying
conductors eel on members and a switch contact D on arms fulcrummed
at f f to a centre insulated piece C which is pivotted to the post at a substantially
as herein described and shown by the appended drawings.
Third. In an overhead system for the electrical transmission of power, the
construction and employment of a switch which maintains contact when both
conductors are in tension and breaks contact directly one or both are ruptured
as herein described and shown by the drawings.
1000
FREDK. WALKER,
73, St. Stephen's Road, Upton Park, London, E.,
Agent for the Applicant.