IMPROVEMENTS IN ELECTRIC SIGNALLING APPARATUS FOR AFFORDING COMMUNICATION BETWEEN PASSENGERS, GUARDS AND DRIVERS OF RAILWAY TRAINS
Year: 1883

page_text: LETTERS PATENT to William Henry Preece F.R.S of Gothic Lodge Wimbledon
in the County of Surrey and William Edward Langdon of the town and
County of Derby Superintendent of Telegraph Department, Midland Railway
Derby for an Invention of "IMPROVEMENTS IN ELECTRIC SIGNALLING
APPARATUS FOR AFFORDING COMMUNICATION BETWEEN PASSENGERS, GUARDS
AND DRIVERS OF RAILWAY TRAINS
"
PROVISIONAL SPECIFICATION left by the said William Henry Preece and
William Edward Langdon at the Office of the Commissioners of Patents on
the 31st March 1883.
WILLIAM HENRY PREECE F.R.S of Gothic Lodge Wimbledon in the County of
Surrey and WILLIAM EDWARD LANGDON of the town and County of Derby,
Superintendent of Telegraph Department, Midland Railway Derby "IMPROVE-
MENTS IN ELECTRIC SIGNALLING APPARATUS FOR AFFORDING COMMUNICATION
BETWEEN PASSENGERS, GUARDS AND DRIVERS OF RAILWAY TRAINS."
The object of this invention is to provide improved and economical appliances
for establishing a means of communication between the various parts of a railway
train in motion or otherwise.
To this end we employ an improved form of coupling so arranged that it requires
but one action to join or couple together the ends of any two vehicles and so
arranged that it can only be coupled up in that manner requisite to ensure the
necessary and proper connection between the wires forming the means of com-
munication. The mechanical portion of this coupling is purposely arranged
similar to the brake coupling employed in certain automatic railway brake
apparatus in order that the mode of coupling both the brake and electric com-
munication may be similarly readily and efficiently dealt with by those whose
duty it is to connect together the several parts of the train as it is made up. At the
upper portion of this coupling which is cylindrical in form, a slot is cut in its

page_text: circumference or periphery, and adjoining this slot is a projection in shape and
size to fit the said slot. At the bottom or opposite side to this slot and projection
is a horn or hook. When the two parts which are practically similar to each other
are placed together, the two horns hooked and the projections from the upper
portion of cach passed into their corresponding slots, the weight of the coupling
together with a cortain projection and corresponding groove in the electrical
connection within the mechanical portion of the coupling holds it together so that
no rain or water can enter, but also so that the parts can easily be separated under
the influence of a straight or direct pull. Within this coupling is fixed the contact
pieces by which the electrical communication is insured and which consists of two
metal springs so arranged that in their normal condition i, e when the coupling is
broken or apart they form contact the one with the other but when set together
this contact or communication is broken and the upper and lower springs of each
coupling alone form contact. To each of these springs are attached the conductors
or wires forming the means of communication.
In order to afford passengers and others a means of communication with the
guard and driver a wire rope or say a rod is passed throughout the length of
the carriage or vehicle one end of which may be rigidly fixed to one end of
the vehicle whilst the other end is fixed to the lever or handle of a commutator
fixed at the end of the said vehicle or each end may be fixed to a commutator.
This wire rope may be carried through the several compartments of a railway
carriage open or it may be partially covered or it may be entirely covered or open
to view through a fixed piece of glass at one or more places within each compart-
ment. The commutator itself is so arranged that in its normal condition the wires
forming the electrical communication are separated but upon the wire rope passing
through the several compartments being pulled in any one of the said compart-
ments the commutator is operated and the electric current caused to flow. Or in
the absence of a fixed commutator the wire rope may be employed to separate the
coupling by being pulled in a like manner from any one of the compartments.
The coupling herein referred to may be employed for a one or two wire means
of communication. It may be applied to any form of railway rolling stock
whether fitted with commutators or not or it may be employed, when provided
with the necessary connecting wires to loop in unfitted stock.
The wire rope in conjunction with the commutator herein referred to may also
be employed for a one or two wire means of communication and the said com-
mutator may or may not as may be desired be provided with an indicator
observable from the exterior of the carriage to indicate the carriage or compart-
ment or commutator at which the communication has been brought into use.
If so required each compartment may be fitted with one or more commutators.
Preferably for the purpose of completing the communication we make use of the
balanced current system for which Letters Patent were granted to the said William
Henry Preece and Alfred Bedborough the 28th day of December in the year 1864
number 3227 and in connection we place within the guards vans, on the engine, or
other vehicles as may be desired bells or indicators which are brought into action
on any one of the commutators being made use of.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said William Henry Preece and William Edward Langdon in the Great
Seal Patent Office on the 29th September 1883.
WILLIAM HENRY PREECE F.R.S. of Gothic Lodge Wimbledon in the County of
Surrey and WILLIAM EDWARD LANGDON of the town and County of Derby
Superintendent of Telegraph Departinent Midland Railway Derby " IMPROVE-
MENTS IN ELECTRIC SIGNALLING APPARATUS FOR AFFORDING COMMUNICATION
BETWEEN PASSENGERS GUARDS AND DRIVERS OF RAILWAY TRAINS "
The object of this invention is to provide improved and economical appliances
for establishing a means of communication between the various parts of a railway
train in motion or otherwise.
To this end we employ an improved form of coupling so arranged that it
requires but one action to join or couple together the ends of any two vehicles
and so arranged that it can only be coupled up in that manner requisite to ensure
the necessary and proper connection between the wires forming the means of
communication. The mechanical portion of this coupling is purposely arranged
similar to the brake coupling employed in certain automatic railway brake
apparatus in order that the mode of coupling both the brake and electric communi-
cation may be similarly readily and efficiently dealt with by those whose duty it
is connect together the several parts of the train as it is made up. At the
upper portion of this coupling which is cylindrical in form, a slut is cut in its
circumference or periphery and adjoining this slot is a projection in shape and size
to fit the said slot. At the bottom or opposite side to this slot and projection is
a horn or hook. When the two parts which are practically similar to each other,
are placed together, the two horns hooked and the projections from the upper
portion of each passed into their corresponding slots the weight of the coupling
together with a certain projection and corresponding groove in the electrical con-
nection within the mechanical portion of the coupling holds it together so that no
rain or water can enter, but also so that the parts can easily be separated under
the influence of a straight or direct pull. Within this coupling is fixed the contact
pieces by which the electrical communication is ensured and which consists of two
metal springs so arranged that in their normal condition i,e, when the coupling is
broken or apart they form contact the one with the other but when set together
this contact or communication is broken and the upper and lower springs of each
coupling alone form contact. To each of these springs are attached the conductors
or wires forming the means of communication.
In order to afford passengers and others a means of communication with the
guard and driver a wire rope or say a rod is passed throughout the length of the
Carriage or vehicle one end of which may be rigidly fixed to one end of the
vehicle whilst the other end is fixed to the lever or handle of a commutator fixed
at the end of the said vehicle (or each end may be fixed to a commutator) This
wire rope may be carried through the several compartments of a railway carriage
open or it may be partially covered or it may be entirely covered and open to
view through a fixed piece of glass at one or more places within each compartment.
The commutator itself is so arranged that in its normal condition the wires
forming the electrical communication are separated but upon the wire rope passing
through the several compartments being pulled in any one of the said compart-
ments the commutator is operated and the electric current caused to flow. Or in
the absence of a fixed commutator the wire rope may be employed to separate the
coupling by being pulled in a like manner from any one of the compartments,

page_text: The coupling herein referred to may be employed for one or two wire means of
communication. It may be applied to any form of railway rolling stock whether
fitted with commutators or not or it may be employed when provided with the
necessary connecting wires to loop in unfitted stock.
The wire rope in conjunction with the commutator herein referred to may also
be employed for a one or two wire means of communication and the said com-
mutator may or may not as may be desired be provided with an indicator
observable from the exterior of the carriage to indicate the carriage or compartment
or commutator at which the communication has been brought into use.
If so
required each compartment may be fitted with one or more commutators.
Preferably for the purpose of completing the communication we make use of the
balanced current system for which Letters Patent were granted to the said
William Henry Preece and Alfred Bedborough the 28th day of September in the
year 1864 number 3227 and in connection we place within the guards vans, on
the engine or other vehicles as may be desired bells or indicators which are
brought into action on any one of the commutators being made use of.
Our improved.. form of coupling is shewn in perspective by Figure 1 in end
view by Figure 2 and in longitudinal section by Figure 3. A A¹ are metal
castings each being similar and cast from the same pattern. At the upper portion
of each is a projection b, b' and adjoining this is a slot c. At the bottom portion
of this casting or opposite to the projection and slot is a hook or horn d d¹
respectively. The slot c is so arranged in each half coupling that the corresponding
projection of the other half of the coupling fits into it and the hook d of the one
engages with the hook d¹ of the other and when thus set together as shown in
Figure 1 the coupling is complete; e Figure 2 is an india rubber washer for making
joint and excluding moisture.
The electrical arrangement within this coupling is composed of two-flat
springs g g Figure 3 fixed to a boss f¹ of ebonite which boss is fixed within the
tubular portion of the casting. To the springs g,g', are fixed ebonite blocks e', e*
faced on their opposite sides by pieces of metal h, h³ which are formed each with
a recess or hollow and a lug. The ebonite blocks are in their transverse section of
the form of triangles sectors or quadrants of a circle so that when the two blocks
from one half coupling are brought together with the two blocks from the other
half coupling they form a square or circular body. Each quadrant is tapered
towards the points e, e¹, and under the influence of the springs g, g', to which the
electrical wires forming the communication are attached, they rest one upon the
other at these extremities.
Each half coupling is fitted alike so that the one may engage with the other.
Thus the part A (Figure 1) is provided with two electrical quadrant shaped blocks
similar to the part A¹. The ebonite blocks being partly faced with metal as shown
in Figure 2 when they are set together the metal face of the one quadrant forms
contact with the metal face of the other, the lug on one fitting in the corresponding
hollow of the other and completes the connection of the two wires which are
connected to the springs gg-thus forming the communication.
When thus set
together the points of contact in one half coupling which touched each other will
by the tapered shape of the quadrants or segments be forced apart at those points
of contact and the lugs on the part h of the one coupling will form contact with
the corresponding hollow on the part h of the other half coupling and the projecting
lug on the part h³ of the one half coupling also in contact with the corresponding
hollow on the part h' of the other half coupling.
Now in order to economise the cost of this means of communication it is proposed
to place within each carriage one electrical commutator only and to operate this
commutator by means of a cord, wire-cable, rod, chain or other convenient means
from the same and other compartments of which the railway carriage is composed,
which cord &c also passes. throughout the interior of the carriage. Thus in
Figure 4 which represents a carriage of four compartments. B, is the commutator
which may be of any ordinary form and a the lever working the same. To the

page_text: lever a is attached the rod or cord 6 which passes throughout the carriage to the
distant end, where it is attached to the extreme end of the carriage. At c
the cord passes through a tube in order to protect it from interference, the points
at which
is exposed for use being those which may be found most suitable for
the purpose. Now on the cord bª being forcibly pulled down to the position shown
in dotted lines by any person in the carriage it will draw over the lever a into the
dotted position which movement will complete the electrical circuit and bring into
operation the bells and other alarm apparatus placed within the Guards vans and
upon the engine.
Where it is thought desirable however any number of commutators may be
employed and they may be worked direct by the passenger, or indirectly by means
of the cord attached thereto as herein explained and the face of this commutator
may be covered by glass, paper or any other substance to prevent its being brought
into use except when required for the purpose of raising an alarm.
And with the object of still further economising the cost of such a communication
the wires employed for conducting the electric current may be employed in the
place of the cord rod or other arrangement for raising the alarm. The said wires
being formed into a cable and to protect it or them against rough usage may be
carried through tubes as at c. in Figure 5, the cable itself being carried through the
ends of the carriage. The aların is then raised by disconnecting the coupling by
pulling the cable 62 downwards until a severance of the coupling d, is produced.
In this case the cable 6 is rigidly fixed at some one central portion of the carriage,
say at f, Figure 5.
In illustration of the operation of the foregoing let it be assumed that the
several carriages composing a train have been coupled up in the same manner as
are the several parts of a train fitted with an automatic brake_apparatus. On
requiring to raise an alarm it is necessary only to pull the cord b Figure 4 in order
to operate the cominutator B when the lever a being drawn over to the dotted
position the electrical circuit is completed and the alarm raised.
Where as in Figure 5 the cord composing the communication is carried through
the ends of the carriage and the alarm is raised by pulling the same until the
coupling is separated, it becomes unnecessary to fix an indicator on the carriage to
show the vehicle from which the aların has been raised, but where as in Figure 4
the communication is brought into operation at the commutator B an indicator
acting in unison with the lever a may be employed so that when the lever a passes
to the dotted position this indicator may show to the guard or others in charge
of the train by its position the carriage in which the commutator has been
operated.
By reference to Figure 2 as also to the previous explanation in reference thereto
it will be seen that when the quadrant blocks e¹ e² are not engaged with the like
blocks of the other half of the coupling they are by the springs g, g' to which
they are connected forced together thus connecting the two wires in each half
coupling; but when the coupling is completed they are thrust apart thus making
through connection of the wires in each half. Now when the coupling is again
pulled apart either as in Figure 5 by pulling the cord b³ from the interior of the
carriage, or as in Figure 4 or Figure 5 by portions of the train becoming detached,
the contacts e, e' will come together the result of which will be the completion of
the electrical circuit at that point and the raising of the alarm in the guards vans
and on the engine.
Having now described the nature of the said invention and in what manner the
same is to be performed we declare that we claim.
First: The combination of the mechanical hook and tongue and slot coupling and
interior electrical quadrant contacts the whole forming an electrical coupling by
means of which the proper relative position of the wires connected to said contacts
is rendered unreversible substantially as set forth.
Second-The combination of a switch or commutator placed at one end of a
railway carriage with a cord or other flexible connection which is fixed at the

page_text: other end of the carriage so as to be available for use from any one of the
compartments of the carriage substantially as set forth.
Third: The combination of the electrical coupling firstly claimed with a
conductor cable which is arranged to pass through the interior of the carriage so
as to be available for use from any one of the compartments for severing the two
halves of the coupling substantially as set forth.
In witness whereof I the said William Edward Langdon for myself and on behalf
of the said William Henry Preece have hereunto set my hand and seal this
Twenty eighth day of September in the year of our Lord One thousand eight
hundred and eightythree
WILLIAM EDWARD LANGDON (L.S.)