IMPROVEMENTS ELECTRICAL SIGNAL OR INDICATOR APPARATUS
Year: 1879

page_text: IN
LETTERS PATENT to Walker Moseley, of Clapham Road, in the County of
Surrey, Electrical Engineer, for the Invention of "IMPROVEMENTS
ELECTRICAL SIGNAL OR INDICATOR APPARATUS."
Sealed the 7th May 1880, and dated the 11th November 1879.
PROVISIONAL SPECIFICATION left by the said Walker Moseley at the Office
of the Commissioners of Patents on the 11th November 1879.
WALKER MOSELEY, of Clapham Road, in the County of Surrey, Electrical
Engineer. "IMPROVEMENTS IN ELECTRICAL SIGNAL OR INDICATOR APPARATUS."
My Invention relates to electrical signal or indicator apparatus chiefly designed to
be used in connection with an electric bell, the purpose of the said apparatus being to
indicate from what room or apartment the bell has been rung, or to convey signals
of various kinds, as may be desired. The said apparatus is applicable for use in
connection with electric bells in houses for calling servants or attendants; it may
also be employed upon railways for signalling purposes; also upon ships for indi-
cating orders to engine drivers or helmsmen, and for any electric signalling purposes
of a similar nature, such, for instance, as gun signals used in the navy.
The chief objects I have in view are to provide an indicator of such form and
construction as will be suitable for all the various purposes for which electric
signals are used, and to obtain greater accuracy of construction and action than
is obtained in the imperfect indicators heretofore in use and without increased
cost.
It is found in practice that the well known electric bell indicator provided with
a polarized magnet pivoted in its centre, and supporting a card at one end and a
balance weight at the other, frequently fails owing to several imperfections that
exist in spite of great care in their make and adjustment; for example, it is found
that the frequent repulsion of the polarised magnet causes the " 'permanent "
magnetism to diminish until it is not sufficient to overcome the counterbalance
weight, hence in order to reduce this evil to a minimum the size of the flag or disc
displayed to show the signal is reduced as much as possible, and yet if this ensures.
its movement when the current is sent through its respective coil of wire it is
found that it is too sensitive to resist any jarring or shaking that occurs in the
neighbourhood of the wall space on which the indicator-case is fixed; moreover,

page_text: a partial and accidental current arising from dampness and imperfect insulation of
wires is found to aggravate the difficulty by causing delicately balanced magnets to
operate wrong signals. To overcome even half these difficulties with the form of
indicator heretofore used, more expense, care, and judgment are required than are
available in all cases in the present state of the trade.
In the Specification of former 'Letters Patent granted to me A.D. 1873, No.
2969, I described means which were partially successful in obtaining the objects
which are fully obtained by my present Invention; but it has been found that the
form and construction of an indicator as described in the said former Specification
requires too much skill and expense to be suitable for general use.
By my present Invention I secure the utmost precision and economy, and the
said Invention is carried into practice in the following manner, that is to say
Upon an oblong iron plate which may be of the following dimensions, namely,
about 2 inches by 1 inch, I fix two iron indicator pillars and on these I fix two
ordinary indicator bobbins. Transversely on this plate I fix a metal frame forming
three sides of a square; at about an eighth of an inch from each end of this frame
I insert a screw with an unscrewed portion of smaller diameter than the screwed
portion at the lower part of the latter. This unscrewed portion is of conical form,
the widest part being at the end farthest from the screw. Pivots are thus formed,
each having a thin edge, upon which I mount a piece of glass tube similar to the
tube of an ordinary thermometer, the ends being ground off at a right angle (or
squared" off); on the upper end of this glass tube I fix a magnet made of clock
spring, which I prefer to be about two inches long by three-eighths of an inch
wide. A half round hollow is formed in the centre of this magnet corresponding with
half the circumference of the glass tube; a short thin piece of soft sheet metal
with a similar hollow fits on the opposite side of the glass tube, and the three
pieces are bound tightly together by bending two overhanging portions of the
sheet metal tightly over the said magnet. Upon one end of this magnet I clip one
or two paper discs, each provided with a thiu wire frame to strain it tight and flat.
If one disc only is used there is a piece of metal to counterbalance the weight of
the paper disc. If two discs are used, one will be white and one black or otherwise
distinguished.
H
The aforesaid metal frame is fixed on the iron plate in such a position that the
magnet can swing over from the bobbin on one side to the bobbin on the other
side, and is so adjusted that the two ends of the magnet rest against the two
bobbins at the same time, so that when a current is sent through one of the
bobbins it repels and throws off one end of the magnet and pulls the other end
towards it with equal power; by this means the permanent magnetism must
naturally be revived or freshened up at every operation, and the magnetic action
operating over double the distance of the one ended form of indicator as heretofore
used, I am enabled to employ a disc 13/8 inches in diameter, and the whole space
occupied is less than a square of three inches compared with a square of four inches
necessary in the form of indicator heretofore used. To secure the magnet in its
place after each operation I attach to the lower end of the permanent magnet &
double ended catch, which overhangs whichever bobbin it rests against, and over
each bobbin is supported a spring latch designed to engage with the above named
catch the weight and momentum of the magnet cause the catch to slide over the
the bevilled end of the spring latch, pressing down the spring in its passage, and
as straight sides oppose each other when closed the magnet cannot be shaken from
its position until the spring is pulled down by the current passing through that
bobbin in the operation of the apparatus. The spring latch is formed of a piece of
very thin tinned iron and passes down the outside of the bobbin, the end being
turned under between the end of the said bobbin and the iron base plate.
The upper part of the aforesaid metal frame will form a convenient support to
receive a card upon which to print the name or number of a room or any desired
signal instead of upon the outer glass covering as heretofore done. I leave a clear
space in the said covering glass through which the card is seen. This arrangement

page_text: is advantageous as the indicators may be made without any numbers or names of
rooms or the like, these being left to be provided according to circumstances at
the time the indicators are fixed. Moreover, means are thus provided for making
nently any changes that may be wanted at any time after fixing.
In order to utilize this improved indicator movement for signals to the engineer
or helmsman in ships, I fix as many of the above described indicators as may be
required in a circle within a metal or wooden case, and in the centre of the latter
is fitted a movable pointer designed to be moved by hand around to the signal
required; the centre of the dial is filled up with a thin spring metal disc or piece,
which can be pressed in ward but will regain its position when pressure is removed.
This disc is suitably connected with mechanism inside the case and which moves
with the said disc, causing contact with the circuit necessary to give the desired
signal upon a corresponding instrument placed in the position required.
The sending and receiving apparatus being similar to each other the person to
whom the signal is sent can in the same manner as is employed for sending the
signal indicate to the sender that the said signal has been correctly given. The
connection with the coil for repelling the magnet to remove the signal when it has
to be replaced by another is effected in the passage of the pointer from one
signal to any other signal in one of the usual methods for producing a rubbing
contact.
Instead of using the ordinary electric bell with this indicator I prefer to employ
a rotary hammer, which is made to strike the bell once or more at every
revolution.
SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Walker Moseley in the Great Seal Patent Office on the 11th May
1880.
"
WALKER MOSELEY, of Clapham Road, in the County of Surrey, Electrical
Engineer. IMPROVEMENTS IN ELECTRICAL SIGNAL OR INDICATOR APPARATUS."
My Invention relates to electrical signal or indicator apparatus chiefly designed
to be used in connection with an electric bell, the purpose of the said apparatus
being to indicate the room or apartment from which the bell has been rung or to
convey signals of various kinds as may be desired. The said apparatus is applicable
for use in connection with electric bells in houses for calling servants or attendants;
it may also be employed upon railways for signalling purposes, and upon ships for
indicating or conveying orders to engine drivers or helms-men, and for any electric
signalling purposes of a similar nature, such for instance as gun signals used in the
navy.
The chief objects I have in view are to provide an indicator of such form and
construction as will be suitable for all the various purposes for which electric
signals are used, and to obtain greater accuracy of construction and action than is

page_text: obtained in the imperfect indicators heretofore in use, and without increased
cost.
It is found in practice that the well known electric bell indicator provided with
a polarized magnet pivoted in its centre, and supporting a card at one end and a
balance weight at the other end, frequently fails by reason of several imperfections
that exist in spite of the great care exercised in their manufacture and adjustment ;
for example, it is found that the frequent repulsion of the polarized magnet causes
the "permanent " magnetism to diminish to such an extent that it is not sufficient
to overcome the counterbalance weight, hence in order to reduce this imperfection to
a minimum the size of the flag or disc displayed to constitute the signal is reduced
as much as possible. Although this construction ensures the movement of the disc
when the current is sent through its respective coil of wire, it is found that the
said disc is too sensitive to resist any jarring or shaking which may occur in the
neighbourhood of the wall space on which the indicator case is fixed; moreover a
partial and accidental current arising from dampness and imperfect iusulation of the
wires is found to aggravate the difficulty by causing delicately balanced magnets to
operate wrong signals. To overcome even a portion of these difficulties with the
forms of indicators heretofore employed, more expense, care, and judgment are
required than are commercially available in all cases in the present state of the
trade.
In the Specification of former Letters Patent dated September 10th, A.D. 1873,
No. 2969, I described means which were partially successful in obtaining the objects
which this Invention is designed to attain, but it has been found in practice that
the form and construction of an indicator as described in the said former Specifica-
tion requires too much skill and expense in its manufacture to suit it for general use.
By my present Invention however I secure the utmost precision and economy in
the manufacture of electrical signal or indicator apparatus.
my Invention; and
Figure 2 is a plan of the same.
Figure 3 is an end view of the said indicator apparatus looking in the direction
of the arrow Figure 1 ; and
Figure 4 is a vertical transverse section of the same on the line x, x, Figure 1.
Figure 5 is an elevation; and
Figure 6, a transverse section of apparatus for conveying signals to persons in
control of marine engines and steering apparatus.
Figure 7 shews a portion of the same detached.
Like letters indicate the same parts throughout the Drawings.
In Figures 1 to 4 a represents an oblong iron plate which may be of the following
dimensions, namely, about 21/, inches x inch; to this plate I fix two iron pillars b
on which are placed two ordinary bobbins c, c'. Upon this plate I fix a metal frame d
forming three sides of a square, and at about an eighth of an inch from each end of
this frame I insert a screw e with an unscrewed portion e¹ of smaller diameter than
the screwed portion e³, as shewn. The unscrewed portions e¹ of these screws are of
conical form, the widest part being at the end farthest from the screw head, and
these portions constitute pivots which have but little surface contacting with the
interior of a piece of glass tube f similar to the tube of an ordinary thermometer.
The ends of this tube are ground off at a right angle (or "squared" off), and on the
front portion of the said glass tube I fix a magnet g. preferably consisting of a flat
plate of metal or of clock spring, and of about two inches long by three eighths of
an inch wide or deep. A half round hollow is formed in the centre of this magnet
corresponding with half the circumference of the glass tube f, and a short thin
piece of soft sheet metal h with a similar hollow fits on the opposite side of the said

page_text: glass tube, the said magnet being securely clamped upon the tube by bending two
overhanging portions of the sheet metal piece h tightly over the said magnet.
Upon one end of this magnet I clip or otherwise fasten two paper discs i, i¹, each of
which is provided with a thin wire frame to strain it tight and flat. The said discs
are of different colors, the disc i being preferably white and the disc black, or the
said discs may be otherwise distinguished. I may in some cases use one disc only,
in which case a piece of metal is attached to the magnet g to counterbalance the
weight of the said disc.
The metal frame d is fixed on the iron plate in such a position that the magnet g
can swing over from the bobbin c on one side to the bobbin c¹ on the other side, the
said magnet, when in its normal position, resting with its two ends against the two
bobbins. When a current of electricity is sent through one of the bobbins c it repels
and throws off one end of the magnet and pulls the other end towards it with equal
power. By this means the permanent magnetism must naturally be revived or
freshened up at every operation, and the magnetic action operating over double the
distance of the form of indicator as heretofore used, I am enabled to employ a disc
13 inches in diameter, and the whole space occupied is less than a square of three
inches, compared with a square of four inches necessary in the form of indicator
heretofore employed. To retain the magnet in position after each movement, and
prevent any liability of the displacement of the same through jarring or other causes,
I attach to one of its ends a double ended catch k, which extends in front of or over-
hangs whichever bobbin the said magnet rests against. In front of each bobbin is
supported a spring latch or armature l, which is provided with an inclined tooth or
projection designed to engage with the catch k. The electro magnetism causes
this catch to slide over the bevelled end of the spring latch 1, pressing down the
spring in its passage, and as the bent portion k¹ of the said catch then rests above
the straight surface of the projection the magnet g cannot be shaken from its
position until the spring latch is attracted by one of the poles or pillars b, when a
current passes through one of the said bobbins in the operation of the apparatus.
The spring latch is formed of a piece of very thin tinned iron, which passes down
the exterior of the bobbin, the end being bent and passed beneath the end of the
said bobbin and the iron base plate a.
The upper part of the metal frame d constitutes a convenient support to receive
a card designating the name or number of a room provided with any desired signal,
thereby obviating the necessity of arranging the same upon the outer glass covering
as heretofore. A clear space is left in the said covering glass through which the
card may be seen. This arrangement is advantageous, as the indicators may be
made without any numbers or names of rooms or the like applied to them, as such
numbers or the like may be readily attached to suit the circumstances and objects
for which the indicators are to be employed when the latter are fixed in position.
Moreover, means are thus provided for enabling any changes that may be desired
at any time after fixing to be readily effected.
In Figures 5, 6, and 7 I have shewn my improvements in indicators for conveying
signals to the person or persons in control of the engines and steering apparatus in
ships. For this purpose I fix as many of the above described indicators as may be
required in a circle within a metal or wooden case m, and in the centre of the said
case I arrange a movable pointer n which may be moved around by hand to the
signal required. The centre of the dial is provided with a thin spring metal piece,
diaphragm, or disc o, which can be pressed inward when desired by applying pressure
to the pointer n at its pivot. The said diaphragm will again regain its position
when pressure is removed. The diaphragm o is so arranged that when pressure is
applied to the pointer na hemispherical knob nt attached to the shank n³ of
the latter will press upon the projection p¹ of one of the springs p, and close
the circuit through one of the arms or spurs q' of a plate or disc q. Between each
of the arms q' of the said plate I arrange a spring arm q', which is bent out of the
plane of the arms q¹, as shewn, so that as the said pointer is rotated, and when at a
ceutral position between each opening or indication in the dial the indicator in the

page_text: apparatus in the engine room or other part of the ship last moved will be returned
to its original or normal position.
From the above description it will be readily understood that when it is desired
to give any order to the person in control of the indicator in the engine or other
room, the said pointer, when moved half way between any two indications on the
order transmitting dial; will cause the former indication on the order receiving dial
to be cancelled, that is to say, the indicator last opérated will be returned to its
normal position. Moreover, the said pointer may be moved over any number of
indications, as, for instance, from "stop" to "full ahead," without affecting the
position of the indicators corresponding to the indications on the dial passed over
by the pointer, as the said pointer does not complete the circuit, and thereby operate
one of the indicators, until the diaphragm o is depressed to close the circuit through
the knob n¹, a projection p¹, one of the arms q' of the plate q, and the connections
to the signal receiving apparatus.
The sending and receiving apparatus being similar to each other, the person to
whom the signal is sent can readily indicate to the sender that the said signal has
been correctly given. The connection with the coil for repelling the magnet to
remove the signal when it has to be replaced by another is effected in the passage
of the pointer from one signal to any other signal, as above described.
Instead of using the ordinary electric bell with this indicator I in some cases
employ a rotary hammer arranged to strike the bell one or more times during each
revolution.
Having thus fully described my Invention, and shewn how the same may be
conveniently and advantageously carried into practice, I wish it understood that I
claim,―
First. In an electric indicator, the spring latch or armature formed of thin tinned
iron in combination with the double catch k attached to the magnet g, substantially
as above set forth and for the purposes specified.
Second. The magnet g pivotted between the bobbins c, c¹, in such a manner that
the ends of the said magnet come alternately into contact with or touch both of the
said bobbins, as above set forth.
Third. The combination with the magnet g of the glass tube for supporting the
same, and the screws e, as above set forth and for the purpose specified.
Fourth. In the apparatus represented in Figures 5 to 7 of the Drawings, the
combination of the pointer n and the thin spring metal piece or diaphragm o with
the other parts of the said apparatus, substantially as above set forth and for the
purpose specified.
In witness whereof, I, the said Walker Moseley, have hereunto set my hand
and seal, this Eleventh day of May; in the year of our Lord One thousand
eight hundred and eighty.
WALKER MOSELEY. (L.S.)