Improvements in Means or Instruments for Testing Submarine Electric Telegraph Cables or for Analogous Purposes.
Year: 1887

page_text: Date of Application, 7th June, 1887
Complete Left, 23rd Feb., 1888
Complete Accepted, 20th Apr., 1888
Improvements in Means or Instruments for Testing Submarine
Electric Telegraph Cables or for Analogous Purposes.
I HERBERT ARNAUD TAYLOR of the Firm of Clark Forde & Taylor of 4 Great
Winchester Street in the City of London Civil Engineers do hereby declare the nature
of this Invention to be as follows :-
My Invention relates more particularly to apparatus for testing submarine electric
telegraph cables but may be used also for analogous purposes and it has for its
principal object to provide apparatus and arrangements which are more efficient in
action than apparatus and means for these purposes as hitherto constructed or
arranged.
According to my Invention I take a number of magnets each with one arm or pole
longer than the other and I place them together in a set one above the other the long
arms being magnetized with one polarity and the short arms with the opposite polarity.
At the side of this set of magnets I place another set of similar magnets but with the
short and long arms magnetized with an opposite polarity to that of the long and
short arms of the first set. I then place the two sets of magnets together the short
poles of each set being placed towards each other and the sets being arranged so that
the magnets do not touch each other. I place both at the bottom and the top of the
two sets of magnets a single horse shoe magnet having poles of the same denomina-
tion as the corresponding poles formed by the long arms of the two sets of magnets.
The spaces
between the magnets may be filled in with brass or other non-magnetic
material. A plate or piece of soft iron is attached to the short arms of the magnets
and a piece of soft iron of a curved shape is fitted to the inner sides of the long arms
of the magnets the concavities of the last named pieces being presented towards the
pieces on the short arins. One or both of the said curved pieces may be made
moveable for enabling the coil of insulated wire to be removed., This may be effected
by making them dovetailed and sliding into corresponding dovetail grooves in the
magnets. Between the said plates and pieces of soft iron is a space in which the said
coil is suspended so as to be capable of moving freely and is provided with a means
for indicating the movements which may be magnified and thrown onto a scale. The
curved form of the pole pieces gives a very uniform field in which the coil moves.

page_text: The aforesaid sets of magnets are secured to a base of insulating material to which are
fitted pillars which carry the coil suspending and adjusting portion of the apparatus
which may consist of two hinged armis fitted with screws for connecting the suspension
wires of the coil. The said hinged arms are supported by a piece capable of moving
in a collar piece held by suspending and adjusting screws passed through a ring. The
pillars may be made hollow for the connecting wires to pass through they being
connected to the arms and to binding screws on the base and the circuits completed in
the usual or any suitable manner.
A
To prevent the coil from being damaged when the instrument is moved from place
to place I arrange a spring immediately under the coil the said spring being moved
by a thumb screw projecting from the side of the base which should be provided with
a level and under the base may be arranged a tangent adjusting screw to the boss of
the wheel of which is applied a locking nut which when unscrewed allows the instru-
ment to be moved round freely without interfering with the tangent screw. The
whole is supported on a tripod the feet of which are fitted with adjusting screws.
piece of soft material is provided beneath the inner pole pieces to prevent the coil
being injured when raised. In place of the sets of magnets arranged as described I
may employ a number of horse-shoe magnets in a single set placed one above the
other the similar poles being placed together and provided with soft iron pole pieces
after the manner already described and the other arrangements may be substantially
as hereinbefore described but the coil in this case will be situated in spaces between
the two poles of the magnets and a central iron piece situated within the coil and
supported from the base or in any other convenient way.
"
When the invention is applied in the form of a differential instrument.I prefer to
pivot the differentially wound coil so that it is suspended on a pivot mounted upon
the central iron piece and the coil is provided with a pointer which moves over a
curved graduated scale to indicate the passage of a current. The pointer is. kept at
zero by opposing spiral springs which serve as conductors to the wires of the
suspended coil (this arrangement is applicable to either a differential circuit or a
single circuit). Binding screws or terminals are provided for the connection of the
wire of the coil. The coil is in some cases preferably wound upon a metal frame and
in some cases I may wraptor cover the wire with a continuous metal strip wound
spirally around the wire and the frame or I may make the coil with an "idle wire
in it the convolutions thereof being insulated or not and in the former case they are
joined to form a closed circuit. The arrangement of the circuit of the instrument
may consist of two resistances connecting three terminals the wires of the aforesaid
coil are connected respectively to two of these terminals (so that they include in a
parallel circuit one of the resistances which acts as a shunt and is adjusted to give the
required damping" when the instrument is on open circuit. The said resistance is
conveniently made about one and a half times as great as the resistance of the
'suspended coil. The other resistance is several times greater than that of the
suspended coil and serves the purpose of preventing over damping when the resistance
aforesaid is short circuited as is necessary in taking an insulation test of a submarine
cable by direct deflection. The instrument can be put in circuit to include the first of
the resistances or both of them as may be most convenient for the observation to be
made Where the aforesaid sheathing by a helically wound strip for the coil or the
idle wire is used the damping is effected by the metal frame and sheathing and can
thus be made more or less independent of the resistance in circuit with the coil so tha
the additional resistances can in this case be dispensed with.
In apparatus constructed or arranged according to my Invention the indications
are given with precision and rapidity obviating much of the uncertainty attaching
to instruments or apparatus as hitherto arranged.
Du är 71, 18 Tuma 1007

page_text: Improvements in Means or Instruments тог Testing Submarine
Electric Telegraph Cables or for Analogous Purposes.
I HERBERT ARNAUD TAYLOR of the firm of Clark Forde & Taylor of 4 Great
Winchester Street in the City of London Civil Engineers 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 more particularly to apparatus for testing submarine electric
telegraph cables but may be used also for analogous purposes and it has for its principal
object to provide apparatus and arrangements which are more efficient in action than
apparatus and means for these purposes as hitherto constructed or arranged.
I will describe my Invention with reference to the accompanying drawings Figures 1
and 2 of which are vertical sections at right angles to each other illustrating one
arrangement of apparatus constructed according to my Invention Figure 3 is a plan
with the cover removed and Figure 4 is a horizontal section taken on the line 1. 2.
Figure 2. The remaining Figures illustrate modifications hereinafter described.
According to my Invention as illustrated in Figures 1 to 4 I arrange a number of
magnets A one above another on a table or platform B one arm or pole A² of each
magnet being longer than the other arm or pole A³ & the long arms being magnetized.
with one polarity and the short arms with the opposite polarity. At the side of this
set of magnets.I place another set of similar magnets C but with the long and short
arms respectively magnetized with polarities opposite to the polarities of the
long and short arms respectively of the first set. I arrange the two sets of magnets A.
and C together so that the short poles of each set are in proximity to each other but
at a short distance apart. At the bottom and the top of the two sets of magnets A.
and C is placed a single horse shoe magnet D having poles of the same denomination
as the correspondingly situated poles formed by the long arms of the two sets of
magnets A and C. The whole of these magnets are secured to the base B by bolts A'
extending from the base up between the arms of the magnets and through holes in a
bar A placed across the arms of the top magnet and forced down thereonto by nuts a'..
The spaces between the magnets may be filled in with brass or other non-magnetic .
material. Plates or pieces of soft iron E of a convex shape are attached to the short
arms of the magnets and pieces D¹ D¹ of soft iron and of a concave shape are fitted.
to the inner sides of the long arms of the magnets the concavities of the last named
One or both of the
pieces being presented towards the pieces E on the short arms.
said curved pieces D' may be made moveable for enabling the coil F of insulated wire
to be removed. In the drawings I have shown one of the pieces D¹ removeable by
forming thereon a dovetail projection c sliding into a corresponding dovetail guide c.
attached to the magnets. Between the said pieces of soft iron E and D¹ is a space in.
which the said coil F is suspended so as to be capable of moving freely, and it is pro->
vided with means for indicating the movements which may be magnified. and thrown

page_text: onto a scale as hereinafter described. The curved form of the pole pieces gives a
very uniform field in which the coil moves. The base B to which the sets of magnets A
C and D are secured is composed of insulating material to which are fitted pillars H
carrying the coil suspending and adjusting portion of the apparatus, which may
consist of two hinged arms I I fitted with screw clamps K for connecting the
suspension wires L of the coil. The hinged arms I are supported by a piece M capable
of moving in a collar piece N held by suspending and adjusting screws passed
through a ring P attached to the pillars H by the arms Q. The pillars H may be
made hollow for the connecting wires to pass through they being connected to the
arms and to binding screws R on the base B the circuits being completed in the
usual or in any suitable manner.
so
To prevent the coil F from being damaged when the instrument is moved from
place to place I arrange a spring S immediately under the coil the said spring being
moved by a thumb screw T projecting from the side of the base B so that the spring
may be brought into position to support the coil F. The base B is provided with a
level U and under the base is arranged a tangent adjusting screw V and worm
wheel W to the boss of which latter is applied a locking screw X which when
unscrewed allows the instrument to be moved round freely on the tripod Y without
interfering with the tangent screw. The whole is supported on the tripod Y the feet
of which are fitted with adjusting screws Z for the purpose of levelling the apparatus.
A piece of soft material a (Figure 2) such as leather for example is provided beneath
the inner pole pieces to prevent the coil from being injured when it is raised. The
whole mechanism is enclosed in a casing b to protect it from injury. In place of the
sets of magnets being arranged as described, a number of horse shoe magnets in a
single set may be employed placed one above the other as shown in Figures 5 and 6,
the similar poles being placed together and provided with soft iron pole pieces D¹ Di
after the manner already described. The other arrangements may be substantially as
hereinbefore described but the coil in this case is situated in the space between the
two poles of the magnets and a central soft iron core E be provided, situated within
the coil and supported from the magnets by a plate d or it may be supported from the
base or in any other convenient way. The coil is not shown in Figures 5 and 6.
Figure 7 shows in elevation partly in section and Figure 8 in plan a differential
instrument constructed according to my Invention. A are the magnets provided with
the soft iron pole pieces D¹ between which I pivot the differentially wound coil
that it is suspended on a pivot'd mounted upon the central iron pole piece E and the
coil is provided with a pointer e which moves over a curved graduated scale fto
indicate the passage of a current. The pointer is kept at zero by opposing spiral
springs which serve as conductors to the wires of the suspended coil. This arrange-
ment is applicable to either a differential circuit or a single circuit. Binding-screws
or terminals R are provided for the connection of the wire of the coil. The coil is in
some cases preferably wound upon a metal frame and in some cases I may wrap,
sheathe or cover the wire with a continuous metal strip wound spirally around the wire
and the frame or I may make the coil with an idle wire" in it, the convolutions
thereof being insulated or not and in the former case they are joined to form a closed
circuit. The arrangement of the circuit of the instrument is illustrated diagramma-
tically in Figure 9, it consists of two resistances connecting three terminals and m
and the wires of the aforesaid coil F are connected respectively to two of these
terminals k and so that they include in a parallel circuit one of the resistances h
which acts as a shunt and is adjusted to give the required "damping" when the
instrument is on open circuit. This resistance is conveniently made about one and a
half times as great as the resistance of the suspended coil. The other resistance i is
several times greater than that of the suspended coil and serves the purpose of pre-
venting over damping when the resistance aforesaid is short circuited (which may be
effected by the plug or key P) which is necessary in taking an insulation test of a
submarine cable by direct deflection. The instrument can be put in circuit to include
one only of the resistances or both of them as may be most convenient for the
observation to be made. Where the sheathing of the coil is by a helically wound
g

page_text: strip or where the idle wire is used, the damping is effected by the metal frame and
sheathing, and can thus be made more or less independent of the resistance in
circuit with the coil so that the additional resistances can in this case be dispensed
with.
In apparatus constructed or arranged according to my invention the indications are
given with precision and rapidity obviating much of the uncertainty attaching to
instruments or apparatus as hitherto arranged.
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 :-
1st. In instruments for testing submarine telegraph cables or for analogous
purposes, a coil of insulated wire suspended in a space between the poles of a series of
magnets the outer poles being provided with removable concave pole pieces whether
the convex pieces on the inner poles be used or not all being constructed and arranged
substantially as and for the purpose hereinbefore described with reference to the
accompanying drawings.
2nd. In instruments for testing submarine telegraph cables and for analogous
purposes a coil of insulated wire suspended on a pivot or pivots between the poles of
a series of magnets and held in position by springs which form part of the electric
circuit substantially as hereinbefore described with reference to Figures 7 and 8 of
the accompanying drawings.
3rd. In instruments for testing submarine telegraph cables and for analogous
purposes a suspended coil of insulated wire wound on a metallic conducting frame in
combination or not with a sheathing of wire wound spirally round the coil substantially
as hereinbefore described.
4th. The general constructions combinations and arrangements of parts constituting
instruments for testing submarine telegraph cables and for analogous purposes as
hereinbefore described and illustrated by the accompanying drawings.
5th. In combination with an instrument constructed or arranged as herein before
described and claimed the arrangement of the circuits with a shunt to the suspended
coil and a resistance in series therewith substantially as herein before described and
illustrated by Figure 9 of the accompanying drawings.
Dated this 0011
T1
1000