IMPROVEMENTS IN APPARATUS FOR PREVENTING COLLISIONS AND ACCIDENTS ON RAILWAYS
Year: 1865

page_text: LETTERS PATENT to William Clark, of 53, Chancery Lane, in the
County of Middlesex, Engineer and Patent Agent, for the Invention of
"IMPROVEMENTS IN APPARATUS FOR PREVENTING COLLISIONS AND
ACCIDENTS ON RAILWAYS."A communication from abroad by Eugene
PROVISIONAL SPECIFICATION left by the said William Clark at the
Office of the Commissioners of Patents, with his Petition, on the 15th
June 1865.
I. WILLIAM CLARK, of 53: Chancery Lane, in the County of Middlesex,
Engineer and Patent Agent, do hereby declare the nature of the said
Invention for "IMPROVEMENTS IN APPARATUS FOR PREVENTING COLLISIONS AND
OTHER ACCIDENTS ON RAILWAYS," to be as follows:-
This Invention relates to apparatus for ensuring the safety of trains on
railways, which apparatus may be actuated either by electricity or by mecha-
nical means. On the locomotive or tender I place a part to which motion is
imparted under certain determined conditions, which has for effect to sound
a whistle or bell, or it may be to turn a disc on the engine; or; lastly, to
operate any suitable signal lamp visible to the driver from the foot plate.
and thereby to give warning of any obstacle to the further onward progress
of the train. I also adapt certain apparatus to the rails fixed at suitable
Price 8d.1

page_text: distances apart and connected together either mechanically or electrically by
means of wires, which apparatus at the required times are caused to effect
contact with the parts or mechanism fixed to the locomotive or tender. This
being understood. I will suppose that a line of rails is provided with the
above-mentioned apparatus throughout its length at equal distances apart of,
say. from four to five thousand yards, and that a train is passing along this
line in a certain direction, which train in passing acts on each apparatus
and indicates the line blocked both before and behind it by rendering the
stop apparatus fixed, while at the same time that the train operates the
fixing, it disengages the stop next beyond that placed in its rear so as to
make the line clear for a succeeding train.
The above is a description of the principle of the Invention, which may be
effected either by mechanical, electrical, or self-acting means, as desired.
The mechanical or electrical combinations for arriving at this result may be
greatly varied, and one of which is represented in the accompanying Draw-
ings as an example only.
The mechanical arrangement to be placed on the engine or tender is
represented in Figs. 1 and 2, and consists of a crank a keyed on the axis or
shaft b, which is fitted horizontally at the required height on the locomotive,
Fig. 3; on this shaft is also keyed a cam c, having at its upper part a
hollow d, in which engages a friction roller e fixed to a lever / oscillating on
point g, and furnished with an adjustable weight serving to regulate the
force with which the roller e acts on cam c. By this adjustment of weight h
a certain amount of pressure is exerted on crank a to retard its rotation;
when crank a comes against a rigid stop it is forced to turn, and by its
rotation raise the friction roller e and lever 1, which latter acts on a pull i in
connection with a signal apparatus placed on the locomotive, as before men-
tioned. The stop with which the crank comes in contact. at certain intervals
consists of apparatus seen in side elevation and back view at Figs. 4 and 5,
and having the exterior form of a box i, at the upper part of which is fitted
a crank turning freely on its axis, against which abuts the crank a placed
on the engine, as seen in Fig. 3. From the foregoing it will be understood
that on a train passing the crank a fixed on the locomotive will strike the
crank on the part j. which crank turns freely on its axis; but if the crank
be rendered rigid in this case the crank on the train will give way and turn
on its axis, as before mentioned, in order to give the alarm signal. I have
stated that the crank mounted on part is free to turn, but may be ren-
dered rigid when desired; this result is obtained by means of the electrical
mechanism seen in Figs. 6, 7, 8, and 9. Fig. 6 shows in principle the

page_text: method by which I liberate or fix the crank k; 1, 1. are two stops carried by
arms or levers s oscillating on points m which stops in advancing or receding.
as shown by the dotted lines. either fix or liberate the crank.
I will now describe the method of actuating this apparatus, by the aid of
electricity, with reference to Figs. 7. 8. 9. and 10. which show different views
of the interior of box or pedestal j: n. bobbins: 0. pallets pivotted at p. and
attracted by the armature q of bobbins : r, pin fixed to one of the arms
of pallets o, and bearing on the arm s. before mentioned. carrying the stop 1.
said arms being provided with a spring on its axis. which serves. 1st, to
return it to such position as to permit of the rotation of crank k, as seen in
Figs. and 8: 2ndly, to separate the pallet o from the armature of the
bobbins; u, stop piece having a space to allow of the passage of the crank :
when stop is advanced it presents itself in front of this space, and so prevents
the crank from passing: in this manner the siop piece u is made to afford
the necessary resistance for holding the crank: a cylindrical commutator
mounted on an axis. and provided with metal parts colored black. and insu-
lating parts left blank in Figs. 8 and 9; y. . . spring plates or contact
surfaces bearing on commutator 2. The plate y communicates on the one
hand with commutator and on the other with the metal axis z of the crank.
which axis is insulated at part of its circumference; 2. pin fixed to the
under plate of crank ; 3, arm fixed to one end of commutator 2: 4. arm
fixed to commutator, and, having a small metal head 5: 6. 6. 6, electric
pile with which each pillar is provided. one of the wires of which communi-
cates with plate : another wire places the plate y in communication with the
bobbins, while the line wire from the bobbins communicates with those of the
next nearest or adjoining apparatus; one wire also passes from axis of crank
in the ground. as do also one of the two wires of pile 6.
In the actual position of the apparatus the action will be as follows:-The
current on leaving the pile rises into the commutator by means of plate y' and
is there arrested; thus the current does not pass into the bobbins, the whole
being placed as shown in the Drawings, and, the crank being free to work
to the right or left is constantly kept up to its normal position by the aid of a
small crank carried by a rod 8 and spring 9. But supposing a train to
pass in the direction of the arrow. Fig. 7, the crank which is free to
oscillate becomes displaced by the crank a fixed on the locomotive, and
describes a quarter circle: in this movement the pin 2 comes in contact with
arm 3 and displaces it to a certain extent, as seen by the dotted lines, which
has for effect to turn the commutator so that the two plates '. y², shall be at
same time in contact with its metallic part; the current then leaves the pile
•

page_text: and passes to plate y', thence to plate y, next to the bobbins, and then to the
line, afterwards entering the adjoining apparatus through the bobbins into
plate next to plate y, and. lastly, passes into the ground through axis z of
crank. The current in passing into the bobbins of the apparatus which is
to be passed serves the purpose of attracting the pallets o of the soft. iron
of the bobbin, which by means of pin r displaces arms, and brings forward
the space of stop lever in order to hold the crank
Immediately the
irain has passed the crank is returned to position by means of spring q. but
the current continues to pass into the bobbins as the arm 4 carrying the small
metal head 5 being by the movement of the crank brought near the soft
iron q remains attached thereto during the whole time the current is passing,
and consequently the crank will be fixed throughout this time. As before
mentioned in the apparatus placed forward the current has passed through
the bobbins, which has for effect to attract the pallets o on the soft iron of the
bobbin, and the stop will consequently arrest the motion of the crank; it
will thus be seen that the train is guarded both in rear and a-head. The
train in continuing its progress, on arriving at the next pedestal will act on
the apparatus therein, as before explained, except that the crank in turning
will displace the insulator 1, and so interrupt the current of the pile 6 of the
apparatus that the train has already passed. while the commutator and
stop being acted on the one by a small spring 10 and the other by spring t
return to their original positions. As an external sign within sight of the
pedestal apparatus, and in front of the hobbins I place a magnetic needle 11
which turns by the passage of the current through the bobbins in such
manner that the guard may know whether a train has entered or left a
certain limit of space.
From the above description it will be seen how by means of electricity I
am enabled to prevent all collisions of trains, whether running in one or both
directions. The apparatus above described and represented serves exclusively
for double lines of railway where trains always run one way on each line; but
supposing there is a single line only, and the trains pass both ways, there
should be a double set of apparatus, that is, on the other side of the crank
there should be another apparatus similar to that described in order that it
may be fixed on either side. These pedestal apparatus may also be made to
act singly; for example, at junctions or near stations for indicating the duties
of the pointsmen, and for working the discs: in the latter case more especially
they may be made to act by mechanical means without the aid of electricity.
an example of which is represented in Fig. 11. k. crank serving as a stop as
before A. stop fixed on the sliding stem B. having an up-and-down motion;

page_text: C, pulley round which a cord or chain D passes to the station; E, arm fixed
on the axis of pulley C; F, pin limiting the motion of arm E; G, weight.
By pulling cord D the pulley is caused to turn, and arm E raises sliding
bar B and stop A so as to hold the crank fixed and form a stop. Imme-
diately the tension on the cord is released the weight G will bring back the
arm and stop to their former position, leaving the crank free to turn as
desired.
Another mechanical means of attaining this result is represented in Figs.
12 and 13. H. pulley . crank keyed on the axis of pulley J: K. stops
limiting the motion of crank [; L. cord passing round the pulley: M. counter-
balance weight. It will be understood that by tightening or slacking the
cord the crank I will assume two positions between stops J. K. in one of
which it forms a stop. and in the other being free to act as desired.
The Invention thus consists, first. in the method or principle described for
insuring the safety of trains; and, secondly, in the arrangements of apparatus
therefor, as herein described and represented, without however being limited
to the precise form or details of the parts of which they are composed.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said William Clark in the Great Seal Patent Office on the
12th December 1865.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I. WILLIAM
CLARK. of 53. Chancery in the County of Middlesex, Engineer and Patent
Agent, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria. by Her Letters
Patent, bearing date the Fifteenth day of June, in the year of our Lord
One thousand eight hundred and sixty-five, in the twenty-eighth year of Her
reign, did, for Herself. Her heirs and successors, give and grant unto mic,
the said William Clark, Her special licence that I, the said William Clark,
my executors. administrators, and assigns, or such others as T. the said
William Clark, my executors, administrators, and assigns, should at any
time agree with, and no others, from time to time and at all times there-
after during the term therein expressed, should and lawfully might make
use, exercise, and vend, within the United Kingdom of Great Britain and
Ireland, the Channel Islands, and Isle of Man, an Invention for "IMPROVEMENTS
IN APPARATUS FOR PREVENTING COLLISIONS AND OTHER ACCIDENTS ON RAILWAYS,"
a communication to me from abroad by Eugene Vincenzi, Engineer, of 29,

page_text: Boulevart St. Martin, Paris, upon the condition (amongst others), that I.
the said William Clark, my executors or administrators. by an instrument in
writing under my, or their, or one of their hands and seals, should particu-
Jarly describe and ascertain the nature of the said Invention. and in what.
manner the same was to be performed, and cause the same to be filed
in the Great Seal. Patent Office within six calendar months next and
immediately after the date of the said Letters Patent.
NOW KNOW YE, that I. the said William Clark, do hereby declare the
nature of the said Invention, and in what manner the same is to be per-
formed, to be particularly described and ascertained in and by the following
statement, reference being had to the two Sheets of Drawings hereunto.
annexed, and to the letters and figures marked thereon (that is to say):
This Invention relates to apparatus for ensuring the safety of trains on
railways, which apparatus may be actuated either by electricity or by
mechanical means. On the locomotive or tender I place a part to which
motion is imparted under certain determined conditions, which has for effect
to sound a whistle or hell, or it may be to turn a disc on the engine, or lastly.
to operate any suitable signal lamp visible by the driver from the foot plate.
and whereby to give warning of any obstacle to the further onward progress
of the train. I also adapt certain apparatus to the rails placed at suitable
distances apart, and connected together either mechanically or electrically by
means of wires, which apparatus at the required times are caused to effect
contact with the parts or mechanism fixed to the locomotive or tender. This
being understood will suppose that a line of rails is provided with the
apparatus above mentioned throughout its length at equal distances apart of.
say, from four to five thousand yards, and that a train is passing along this
line in a certain direction, which train in passing acts on each apparatus, and
indicates the line blocked both before and behind it by rendering the stop
apparatus fixed, while at same time that the train operates the fixing it
disengages the stop next beyond that placed at its rear, so as to make the line
clear for a succeeding train.
The above is a description of the principle of the Invention, which may be
effected either by mechanical, electrical, or self-acting means, as desired.
The mechanical or electrical combinations for arriving at this result may be
greatly varied, and one of which is represented in the accompanying Drawings
as an example only.
The mechanical arrangement to be placed on the engine or tender is
represented in Figs. 1 and 2, and consists of a crank arm a keyed on an axis
or shaft b, which is fitted horizontally at the required height on the locomotive

page_text: Fig. 3 on this shaft is also keyed a cam e, having at its upper part a
hollow d, in which engages a friction roller e fixed to a lever f. oscillating at
point g. and furnished with an adjustable weight h. serving to regulate the
force with which the roller c acts on cam c. By this adjustment of weight ha
certain amount of pressure is exerted on crank a to retard its rotation.
When crank arm a comes against a rigid stop it is forced to turn, & by its
rotation raise the friction roller e and lever /, which latter acts on a pull i in
connection with a signal apparatus placed on the locomotive, as before
mentioned. The stops with which the crank arm comes in contact at certain
intervals consist of apparatus seen in side elevation and back view at Figs. 4
and 5, and having the exterior form of a box j, at the upper part of which is
fitted a crank arm turning freely on its axis, and against which abuts the
crank arm a placed on the engine as seen in Fig. 3. From the foregoing it
will be understood that on a train passing the crank arm a fixed on the
locomotive will strike the crank arm on the part, which crank turns freely
on its axis; but if crank arm & be rendered rigid in this case the crank arm a
on the train will give way and turn on its axis. as before mentioned, in order
to give the alarm signal. I have stated that the crank arm mounted on
part is free to turn. but may be rendered fixed or rigid when desired; the
result is obtained by means of the electrical mechanism seen in Figs. 6, 7,
8. and 9. Fig. 6 shows in principle the method by which I liberate or fix
the crank : 1. 1. are two stops carried by arms or levers s, s, oscillating on
points m, which in advancing or receding, as shown by the dotted lines,
either fix or liberate the crank.
I will now describe the method of actuating this apparatus by the aid of
electricity with reference to Figs. 7, 8, 9, and 10, which show different views
of the interior of box or pedestal : #, bobbins; o pallets pivotted at p, and
attracted by the armature of bobbins n; r, pin fixed to one of the arms of
pallets o, and bearing on the arm s. before mentioned. carrying the stop 1;
said arms being provided with a spring on its axis serving. Ist, io return it
to such position as to permit of the rotation of crank k, as seen in Figs. 7
and 8: 2ndly. to separate the pallets o from the armature of the bobbins;
, stop piece having a space to allow of the passage of the crank ; when
stop is advanced. it presents itself in front of this space. and so prevents the
crank from passing; in this manner the stop piece is made to allow the
necessary resistance for holding the crank; z, cylindrical commutator mounted
on an axis and provided with metal parts colored black, and insulated parts
left blank in Figs. 8 and 9; . . . spring plates on contact surfaces bearing
on commutator z. The plate
communicates on the one hand with com-

page_text: mutator, and on the other with the metal axis z of the crank, which axis is
insulated at part 1 of its circumference; 2, pin fixed to the under part of
crank ; 3, arm fixed to one end of commutator ; 4, arm fixed to com-
mutator, and having a small metal head 5, 6, 6, 6, electric pile with
which each pillar is provided, one of the wires of which communicates with
plate y, another wire places the plate in communication with the bobbins,
while the line wire from the bobbins communicates with those of the next
nearest, or adjoining apparatus; one wire also passes from axis of crank k
into the ground, as do also one of the two wires of pile 6.
which is free
In the actual position of the apparatus the action will be as follows:-The
current on leaving the pile rises into the commutator by means of plate y'.
and is there arrested; thus the current does not pass into the bobbins, the
whole being placed as shewn in the Drawings, and the crank being free to
work to the right or left, and is constantly kept up to its normal position by
the aid of a small crank 7 carried by a rod 8 and spring 9. But supposing
a train to pass in the direction of the arrow, Fig. 7, the crank
to oscillate, becomes displaced by the crank a fixed on the locomotive, and
describes a quarter circle; in this movement the pin 2 comes in contact with
arm 3, and displaces it to a certain extent, as seen by the dotted lines, which
has for effect to turn the commutator so that the two plates y', y, shall be at
same time in contact with its metallic part, the current then leaves the pile
and passes to the plate y', thence to the plate next to the bobbins, and
then into the line, afterwards entering the adjoining apparatus through the
bobbins into plate next to plate y, and lastly passes into the ground
through axis z of crank h. The current in passing into the bobbins of the
apparatus which is to be passed serves the purpose of attracting the pallets o
on the soft iron of the bobbin, which by means of pin r displaces arm s, and
brings forward the space of stop lever I, in order to hold the crank k.
Immediately the train has passed the crank is returned to position by
means of spring g, but the current continues to pass into the bobbins as the
arm 4 carrying the small metal head 5 being by the movement of crank
brought near the soft iron g, remains attached thereto during the whole time
the current is passing, and consequently the crank will be fixed throughout
this time. As before mentioned in the apparatus placed forward the current
has passed through the bobbins, which has for effect to attract the pallets o
on the soft iron of the bobbin, and the stop will consequently arrest the
motion of the crank. It will thus be seen that the train is guarded both in
rear and ahead. The train is continuing its progress on arriving at the next
pedestal will act on the apparatus therein, as before explained, except that

page_text: the crank in turning will displace the insulator 1, and so interrupt the
current of the pile 6 of the apparatus, that the train has already passed, while
the commutator and stop 1 being acted on the one by a small spring 10 and
the other by spring . return to their original positions..
As an external sign within sight of the guard or driver, I place on each
pedestal apparatus and in front of the bobbins a magnetic needle 11, which
turns by the passage of the current through the bobbins in such manner that
the guard may know whether a train has entered or left a certain limit of space.
From the above description it will be seen how by means of electricity I
am enabled to prevent all collisions of trains, whether running in one or both
directions. The apparatus above described and represented serves exclusively
for double lines of railway where trains always pass one way on each line, but
supposing there is a single line only, and the trains pass both ways, there
should be a double set of apparatus, that is, on the other side of the crank
there should be another apparatus similar to that described, in order that it
may be fixed on either side. These pedestal apparatus may also be made to
act singly; for example, at junctions or near stations for indicating the duties
of the pointsman, and for working the discs; in the latter case more
especially they may be made to act by mechanical means without the aid of
electricity, an example of which is represented in Fig. 11. , crank serving
as a stop as before; A, stop fixed on a sliding stem B, having an up-and-down
motion; C, pulley, round which a cord or chain D passes to the station;
E, arm fixed on the axis of pulley C; F, pin limiting the motion of arm E;
G, weight. By pulling cord D the pulley is caused to turn, and arm E
raises sliding bar B and stop A, so as to hold the crank fixed and form a
stop. Immediately the tension on the cord is released the weight G will
bring back the arm and stop to their former position, leaving the crank
free to turn as desired.
Another mechanical means of attaining this result is represented in Figs.
12 and 13. H, pulley; I, crank keyed on the axis of pulley J, K, stops
limiting the motion of crank I; L, cord passing round the pulley; M, coun-
terbalance weight. It will be understood that by tightening or slacking
the cord L the crank I will assume two positions between stops J, K, in one
of which it forms a stop, and in the other being free to act as desired.
Having described the nature of this Invention, and the manner of per-
forming the same, I declare that what I claim as the Invention to be pro-
tected by the herein-before in part recited Letters Patent is,-
1st, the method or principle herein-before described for ensuring the safety
of trains.

page_text: 2ndly, I claim the employment of mechanical means or electricity, or both
in combination, for effecting said purpose in the manner described.
3rdly, claim the arrangements of apparatus for ensuring the safety of
trains, as herein described and represented, without, however, being limited
to the precise form or details of the parts of which they are composed.
4thly, I claim the arrangement of electro-magnet n, represented at Fig. 10.
for the purposes of this Invention, which possesses great attractive power.
In witness whereof, I, the said William Clark, have hereunto set my
hand and seal, this Eleventh day of December, in the year of our
Lord One thousand eight hundred and sixty-five.
Witness,
W. G. E. SWINNOCK,
53, Chancery Lane,
London.
W. CLARK. (L.S.)