Improvements in and relating to the Electrical Communication of Signals.
Year: 1898

page_text: Date of Application, 7th Oct., 1898
Complete Specification Left, 7th July, 1899-Accepted, 19th Aug.,
1899
Improvements in and relating to the Electrical Communication of
Signals.
We, HENRY MECHAN, of the Firm of Mechan and Sons, Neptune Iron, Brass
and Copper Works, 60, Elliot Street, Cranstonhill, Brassfounders, and DAVID
MUIRHEAD, of 149, Rutherglen Road, Mechanic, both in the County of the City
of Glasgow, do hereby declare the nature of our invention to be as follows:-
This invention has reference to and comprises improvements in and relating to
the electrical communication of signals and the arrangement or combination of
the parts or devices for effecting same, which though more particularly designed
for use on board steam ships for electrically telegraphing signals from the captain's
bridge to the engine room and vice versa, or to other parts of the vessel, are also
capable of adaptation for electrically communicating signals where ever such devices
can be usefully and conveniently employed.
As applied for communicating signals between the bridge of a steam ship and
the engine room the improvements essentially consist in devices for actuating a
pointer revolving in front of a dial, on which the various orders or signals are
indicated, by means of an electric current controlled by mechanism on the bridge,
and returning a reply or confirmation of the signal to the bridge, at the same
time causing electric bells to ring to attract attention, and these devices are
capable of considerable modification.
"
According to one modification a casing, preferably circular, is erected in the engine
room, closed in front by a glazed cover behind which a dial is fitted around which
are marked the various signals which may be " stop "stand by" "dead slow"
"half speed" "full speed" the latter four being duplicated on the dial on each side
of "stop" with the words "ahead" and "astern" to distinguish the sets, one being
for movement ahead and the other for movement astern. A spindle is mounted in
bearings in the back of the casing and a small bracket and projects through the dial,
and a pointer is secured on the outer end of this spindle.
When the current is switched on to the magnets it is simultaneously switched on
to an electric bell, there being preferably two bells of different tones used, one
for ahead signals and one for astern, and these bells may also be placed on the
bridge so that when a signal is passed from the bridge a confirming signal is
received there.
The signals may be communicated from the bridge by switching on the electric
current by means of ordinary pushes, one for ahead and one for astern, such as are
used for electric bells and these pushes may be actuated by levers so that the operator
may be certain of their being pushed home. Otherwise however, the electric current
may be switched on by means of a radial handle turning a spindle carried in a casing
having a duplicate dial and pointer on spindle end fitted in front of same. Within
this casing a disc, or segment of a disc, of wood or other insulating material is secured,

page_text: having notches cut out of its periphery at spaced distances corresponding to the
divisions of the dial, thus forming a series of wide teeth with spaces between them.
The wire leading to the magnets and bells are secured around the sides of this dise
one side for ahead signals and the other for astern signals and these wires are
connected to metal plates covering each side of the teeth but not touching each other.
A radial arm projecting from the spindle and parallel to the handle is reverted at its
end and carries a contact in the form of a blade spring twisted so that it lies normally
in a diagonal position in the spaces between the teeth. This arrangement causes it
when moved in one direction to make contact with the plates on one side of the disc
and when moved in the other direction to make contact with the plates on the reverse
side, thus bringing into action the ahead or astern signals accordingly as it is moved.
The current is carried to the spindle by means of a contact plate kept pressed against
it by means of a spring, or it may be by an eye around the spindle connected to the
wire from the batteries by a spiral spring.
Fitted in the described manner the mid position of the handle and pointer is
opposite stop. When the handle is moved one space towards the set of signals for
ahead the contact passes along side of one tooth of the disc and switches on the
current which causes the electric bells to ring in the engine room and on the bridge
and causes the electro magnets to actuate the pointers through one space of the dials,
and when the handle is moved in the opposite direction the contact passes along the
other side of the tooth and brings into action the other set of magnets and this action
is repeated for each space or signal on the dial.
A duplex ratchet wheel having two sets of ratchet teeth arranged in opposite
directions is secured on the spindle of the dial and is rotated by pawls actuated by
the armatures of electric magnets one on each side for each set of signals ahead and
astern. Each pawl is jointed to a rod pendent from and jointed to the end of the
armature and guided at its lower end by passing through a hole in the bracket.
The pawl is formed with a projection or tooth to engage with the ratchet wheel and
when out of action rests on the bracket carrying the outer end of the spindle by
which it is pressed out of contact with the ratchet wheel, but when raised, by the
attraction of the armature to the magnets by the switching on of the current, it is
pressed into contact with the ratchet wheel by means of a blade spring secured to the
rod acting on it, and turns same and moves the pointer equal to one space on the
dial while a projecting heel on the pawl engages with the ratchet tooth to prevent
the pointer flying round too far. To hold the spindle and pointer steady a sinall
wheel is secured on the spindle having its periphery recessed at spaced distances to
correspond with the divisions on the dial and a sinal roller carried on the end of a
spring engages with these recesses to hold the spindle steady.
Instead of having a pointer on the handle spindle of bridge dial a projection on the
handle may be turned down over the casing to point inwards and indicate the divi-
sions over which it travels and a spindle and pointer actuated by electro magnets
within the casing may be used to give the confirming or answering signal to the
bridge.
It will be evident that though the improvements have been described as applied
between the bridge and the engine room of a steam ship, they could equally well be
applied between any other parts for instance to convey signals to the men working at
the mooring ropes, also that any desired set of signals could be communicated
between any points desired where the described devices could be conveniently
applied.
Dated the oth dor of Ostabox 1000

page_text: COMPLETE SPECIFICATION.
Improvements in and relating to the Electrical Communication of
Signals.
We, HENRY MECHAN, of the Firm of Mechan and Sons, Neptune Iron, Brass and
Copper Works, 60, Elliot Street, Cranstonhill, Brass founders, and DAVID MUIRHEAD,
of 149, Rutherglen Road, Mechanic, both in the County of the City of Glasgow, do
hereby declare the nature of our invention and in what manner the same is to be
performed to be particularly described and ascertained in and by the following
statement in writing, reference being made to the accompanying drawings:-
This invention has reference to and comprises improvements in and relating to the
electrical communication of signals and the arrangement or combination of the parts
of devices for effecting same, which though more particularly designed for use on
board steam ship for electrically telegraphing signals from the captain's bridge to
the engine room and vice versa, or to other parts of the vessel, are also capable of
adaptation for electrically communicating signals wherever such devices can be use-
fully and conveniently employed.
As applied for communicating signals between the bridge of the steam ship and
the engine room the improvements essentially consist in devices for actuating a
pointer revolving in front of a dial, on which the various orders or signals are indicated,
by means of an electric current controlled by switch mechanism or pushes on the
bridge, and returning a reply or confirmation of the signal to the bridge, at the same
time causing electric bells to ring to attract attention and these devices are capable
of considerable modification.
And in order that our said invention may be properly understood we have hereunto
appended one sheet of explanatory drawings in which Figure 1 illustrates the electric
mechanism behind the dial, removed in this case, for moving the pointer, Figure 1*
being a partial plan to an enlarged scale, while Figure 2 illustrates the confirming
dial on the captain's bridge which with its mechanism is in all respects a duplicate of
that illustrated by Figure 1, and Figure 3 and 3 illustrate the switching device.
Referring to these drawings
:―
A casing A, preferably circular, is erected in the engine room and on the bridge
closed in front by a glazed cover behind which a dial B is fitted around which are
marked the various signals which may be " stop"
""stand by ""dead slow"
""half
speed ""full speed," the latter four being duplicated on the dial on each side of
"stop" with the words "ahead" and "astern" to distinguish the sets, one being for
movement ahead and the other for movement astern.
A spindle C is mounted in bearings in the back of the casing and a small
bracket C¹ and projects through the dial B, and a pointer D is secured on the outer
end of this spindle C which is turned by switching the current from an ordinary
battery or other source of electricity on to electro magnets in the manner to be
described. When the current is switched on to the magnets it is simultaneously
switched on to an electric bell or bells, not shown in the drawings, there being
preferably two bells of different tones used, one for ahead signals and one for astern,
and these bells as well as the confirming dial and mechanisin may also be placed
on the bridge so that when a signal is passed from the bridge a confirming signal is
received there.
The signals may be communicated from the bridge by switching on the electric
current by means of ordinary pushes E, as shown in Figure 2, one for ahead and
one for astern, such as are used for electric bells and these pushes may if so desired
be actuated by levers so that the operator may be certain of their being pushed
home. Otherwise however as illustrated by Figures and 3, respectively an

page_text: elevation and a plan, the electric current inay be switched on by means of a radial
handle F turning a spindle F1 carried in a casing having a duplicate dial F+ and
pointer F5 on spindle end fitted in front of same. Within this casing a disc, or
as shown, a segment of a disc G, of wood or other insulating material is secured,
having notches cut out of its periphery at spaced distances corresponding to the
divisions of the dial, thus forming a series of wide teeth with spaces between
them. The wires g¹ g² leading to the magnets and bells are secured around the
sides of this disc G on one side g₁ for ahead signals and the other 2 for astern
signals and these wires are connected to metal plates g³ covering each side of the
teeth but not touching each other. A radial arm f projecting from the spindle F1
and parallel to the handle is reverted at its end and carries a contact fi in the
form of a blade spring twisted so that it lies normally in a diagonal position in the
spaces between the teeth g. This arrangement causes it when moved in one direction
to make contact with the plates on one side of the disc and when moved in the other
direction to make contact with the plates on the reverse side, thus bringing into action
the ahead or astern signals accordingly as it is moved. The current is carried to the
spindle by means of a contact plate 91 kept pressed against it by means of a spring,
as shown, or it may be by an eye around the spindle connected to the wire from the
batteries by a spiral spring.
Fitted in the described manner the mid position of the handle and pointer is oppo-
site stop. When the handle is moved one space towards the set of signals as for
ahead the contact passes alongside of one tooth of the disc and switches on the current
which causes the electric bells to ring in the engine room and on the bridge and
causes the electric magnets to actuate the pointers through one space of the dials, and
when the handle is moved in the opposite direction the contact passes along the other
side of the tooth and brings into action the other set of magnets and this action is
repeated for each space or signal on the dial.
The arrangement of the pointer moving mechanism illustrated by Figures 1 and 1^
is as follows-A duplex ratchet wheel H having two sets of ratchet teeth arranged in
opposite directions is secured on the spindle C of the dial B and is rotated by pawls I
actuated by the armatures J of electric magnets L one on each side for each set of
signals ahead and astern. Each pawl I is jointed to a rod I¹ pendent from and jointed
to the end of the armature J and guided at its lower end by passing through a hole
in the bracket C¹. The pawls are formed with a projection or tooth 12 to engage with
the ratchet wheel and when out of action rests on the bracket C¹ carrying the outer
end of the spindle by which it is pressed out of contact with the ratchet wheel H, but
when raised, by the attraction of the armature to the magnets by the switching on of
the current, it is pressed into contact with the ratchet wheel by means of a blade
spring 13 secured to the rod acting on it, and turns same and moves the pointer equal
to one space on the dial, while a projecting heel 14 on the pawl engages with the
ratchet tooth to prevent the pointer flying round too far. To hold the spindle and
pointer steady a small wheel K is secured on the spindle having its periphery recessed
at spaced distances to correspond with the divisions on the dial and a small roller i
carried on the end of a spring engages with these recesses to hold the spindle
steady.
Instead of having a pointer on the handle spindle F1 of bridge dial F' a projection
on the handle may be turned down over the casing to point inwards and indicate the
divisions over which it travels and a spindle and pointer actuated by electro magnets
within the casing in a similar manner to that shown may be used to give the con-
firming or answering signal to the bridge.
The necessary wiring between the battery and the bells and electro magnets is all
fitted in the ordinary well known manner and is therefore not illustrated.
It will be evident that though the improvements have been described as applied
between the bridge and the engine room of a steam ship, they could equally well be
applied between any other parts for instance to convey signals to the men working at
the mooring ropes also that any desired set of signals could be communicated

page_text: between any points desired where the described devices could be conveniently
applied.
Having now particularly described and ascertained the nature of our said inven-
tion and in what manner the same is to be performed we declare that what we
claim is :-
First. The system of and apparatus for conveying electric signals on board ship or
where applicable all substantially as herein described and illustrated by the accompany-
ing drawings.
Second. In a system for conveying electric signals on board ship or where applicable,
the combination of a battery, a switching device, bells, and electro-magnets operating
pointers through pawl mechanism, all electrically connected substantially as herein
described and illustrated by the accompanying drawings.
Third. In a system for conveying electric signals on board ship or where applicable
the combination of a battery, bells, and electro magnets operating pointers through
pawl mechanism, electrically connected and worked by pushes substantially as herein
described and illustrated by Figures 1 1 and 2 of the accompanying drawings.
Fourth. In a system for conveying electric signals on board ship or where applicable
the arrangement of duplex ratchet wheel and pawl mechanism actuated by electro
magnets substantially as herein described and illustrated by Figures 1 and 1ª of the
accompanying drawings.
Dated the 6th July 1899