IMPROVEMENTS IN APPARATUS FOR CHECKING AND RECORDING THE SPEED OF TRAINS PASSING OVER RAILWAY BRIDGES GRADIENTS OR OTHER PARTS OF THE PERMANENT WAY
Year: 1882

page_text: "
LETTERS PATENT to George Frederick Redfern, of the General Patent Office,
No. 4, South Street, Finsbury, in the county of Middlesex, Patent Agent
for an invention of IMPROVEMENTS IN APPARATUS FOR CHECKING AND
RECORDING THE SPEED OF TRAINS PASSING OVER RAILWAY BRIDGES GRADIENTS
OR OTHER PARTS OF THE PERMANENT WAY."-A communication from abroad
by Jan Herman Marie Waldorp of Nymegen, in the kingdom of Holland,
Civil Engineer
PROVISIONAL SPECIFICATION left by the said George Frederick Redfern
at the Office of the Commissioners of Patents on the 1st March 1882.
GEORGE FREDERICK REDFERN, of the General Patent Office No. 4 South Street
Finsbury in the county of Middlesex, Patent Agent, "IMPROVEMENTS IN APPARATUS
FOR CHECKING AND RECORDING THE SPEED OF TRAINS PASSING OVER RAILWAY
BRIDGES GRADIENTS OR OTHER PARTS OF THE PERMANENT WAY." [A communi-
cation from abroad by Jan Herman Marie Waldorp of Nymegen, in the kingdom
of Holland, Civil Engineer.]
The constantly increasing weight of the loads carried by railway trains, has
latterly caused attention to be directed to the necessity of limiting the speed of
such trains when passing over iron railway bridges, in the interest of the security
and the preservation of such bridges, and in some countries regulations have
already been enacted in this direction, amongst others in the Kingdom of Holland
where the speed at which trains are allowed to pass over bridges is limited to
thirty kilometers (about eighteen and a half miles) an hour. Now the object of
this invention is to provide mechanism and apparatus for registering this speed.
Such mechanism of which the registering or recording apparatus constitutes an
integral part, should, to be of any real value for the purpose for which it is
intended, combine the following properties.
(1). The mechanism should work automatically without the intervention of the

page_text: employé charged with taking with taking off the records as the only duty of this
employé should be to see to the regular working of the mechanism and to preparo
the instrument for receiving the records.
(2). The apparatus for receiving and marking the records should be placed
within the immediate reach of the said employé and should by preference be
placed in the office of the station superintendent and it should be enclosed in such
a manner that no other person than he can touch it.
(3). The records should comprise a series of trains passing during a space of
time of twenty four hours for example without it being necessary for the employé
to touch the apparatus.
(4). The records should be such, if required, as to separately indicate the speed
of the trains at various parts of the bridge.
None of the apparatuses at present in use fulfil these combined conditions, they
consequently give inexact results and therefore cannot be relied on.
Some of the said apparatuses indicate the speed (notably the Leboulanger
system) by means of a needle moving over a dial; by observing the space passed
over by the needle the speed of the train is calculated whilst the needle has to be
brought back to zero for the next train.
Others (such as those used on the Netherland States Railways) indicate the
progress of the train over the bridge on a band or ribbon of paper by means of a
wheel coated with ink in a similar manner to that by which the Morse apparatus
transmits telegraphic symbols and to cause the paper band to unroll, the employé
each time a train is expected has to put the apparatus in movement and to stop it
when the train has passed. The speed is calculated by measuring on the band of
paper the distance between the point where the wheel commenced to mark at the
entrance of the train and the point at which the wheel ceased to mark when the
train left the bridge.
The mechanism and apparatus hereinafter described are free from the objections
common to those employed until now.
The improved mechanism and apparatus may be divided into two distinct parts,
videlicet:
(A). The mechanism (or bridge apparatus) on the bridge itself consisting of a
certain number of contact points which communicate the passage of the wheels of
the train to; (B) an apparatus placed in the inspector's office of the nearest station
where the said contacts are recorded.
In the bridge apparatus (which is somewhat similar to those which the Nether-
land States Railway has applied to several bridges) the said contact points are
applied either only at both ends of the bridge or at intermediate points according
to the length of the bridge.
At a short distance above the rail is placed what may be termed a treadle
constructed of a piece of steel on the end of a horizontal rod. When the rod
turns, a link is moved upwards moving with it a bar, thereby placing two contact
plates in contact.
From the knobs on these plates pass conducting wires terminating at the station
as hereinafter described. By this means on the pressure of each wheel of the train
on the treadle the horizontal rod turns, the bar is raised and the plates are put in
contact. A piece of india rubber applied under the treadle, and steel wire spiral
springs around the bar cause these two pieces to retake their normal position after
each wheel has passed and established contact between the plates.
The station apparatus is constructed substantially as follows:-
A clock movement is employed operated by a spring and regulated by means of
a fly pinion of a strength sufficient to cause a shaft to make each of its revolutions
in the same period of time.
A cylinder follows the rotation of the said shaft and consequently accomplishes
one revolution in the same time; on the said cylinder is marked the space of time
which the train occupies in passing.
An arrangement of mechanism constructed as hereinafter described is employed

page_text: to set the clock movement going as soon as the train reaches the bridge and to
stop it after the train has passed.
An apparatus constructed as hereinafter described transmits, to the cylinder the
contacts which have taken place on the bridge by the treadles during the passage
of the train over the bridge in such a manner that the distance existing between
the two contacts recorded taken in connection with the speed of rotation of the
cylinder will indicate the time the train bas been on the bridge between the two
treadles when these are placed at both ends of the bridge.
It will be evident that in this manner by establishing several treadles the speed
of the train over various parts of the bridge may be checked and registered.
The clock movement is constructed of an arrangement of wheel work contained
in a box and moved by a spring in a barrel, which is wound up by means of a
handle. The movement of the clock is regulated by a fly pinion. The number of
seconds in which it is desired that the shaft shall make one revolution is regulated
by weighting or lightening the fly-pinion. The shaft extends outside the box and
is provided at one of its ends with a pin which serves to communicate a rotating
movement to a cylinder made of suitable sheet metal and fixed on a horizontal
shaft working in supports and carrying at one of its ends a small fork into which
takes a pin in such a manner that the main shaft in turning moves the horizontal
shaft and with it the cylinder.
Every morning before the arrival of the first train the cylinder is covered with
paper coated with white lead blackened over a paraffin lamp as hereinafter
described. The back of the paper is divided by means of horizontal lines into as
many bands as there are seconds of time in one revolution of the cylinder
The length of the cylinder is regulated according to the number of trains to be
registered on the same paper band and will depend on the speed with which the
marking needle or hand hereinafter described passes over the cylinder.
To prepare the cylinder for registering, its shaft is taken from the support and
the cylinder covered with paper one end of which is coated with gum; it is placed
in a wooden apparatus in the supports of which the cylinder is turned, a petroleum
lamp being placed underneath so that the paper becomes covered with lamp
black.
As soon as the trains which are to be registered have passed, the paper is cut
and removed from the cylinder and plunged in a bath of gum lac and alcohol for
the purpose of fixing the records. The paper is then suspended on the wooden
cross bar of the bath to allow it to drain and dry.
I will now describe the apparatus for starting and stopping the clock movement.
When a train comes on the bridge each wheel, as has been already described,
presses on the treadle and causes the two plates to make contact.
These plates
communicate by means of a conducting wire with an electro-magnet consisting of
two bobbins on a core of soft iron over which is placed an armature or anchor.
An electric current will thus be set up which passing through the bobbins and
communicating with the soft iron core will attract the anchor or armature the tail
of which turning on an axis will thereby be raised. The tail presses on the under-
side of one of the arms of a cranked lever, such lever turning on a small horizontal
pivot. The said lever arm is provided with a small sliding counterweight and
with a catch in the form of a knife and the end of the lever presses on the side of
a spring which is attached to a horizontal shaft; the other arm of the lever
terminates with a stop button which in a certain position of the lever presses an
ebonite plate forming part of the vertical shaft of the fly pinion.
To the same support which carries the small arbor of the lever is fixed the pivot
of a small curved rod the elbow of which presses under the hereinbefore described
arm under the bend of the lever.
The said lever with its accessories has for object the starting and stopping of the
clockwork.
The parts being in the position described and the spring in the barrel being
wound up, the movement of the clockwork may be stopped by pressing a button

page_text: against the ebonite plate of the fly; in all cases as soon as the anchor or armature
is attracted the tail thereof raises one of the arms of the lever which causes the
button part thereof, to descend in such a manner that the fly becomes free and the
wheelwork commences to move. The fall of the lever into its normal position by
the breaking of the current and the release of the anchor or armature is prevented
by the pressure of the end of the lever arm against the spring.
The stoppage of the clockwork is produced in the following manner; after one
revolution of the main shaft, a pin on the wheel of this shaft throws off a small
curved rod or striker from which it follows that the movement of this latter raises
one of the arms of the lever near the bend, detaches the other arm from the spring
and presses the knob against the ebonite plate. At the same time the catch in the
form of a knife falls into the notch of a small wheel fixed on the same shaft.
The records on the cylinder are produced as follows;-The main shaft, as herein-
before described, communicates its rotary movement to the cylinder against which
is placed the needle constructed of a small plate of steel of a pointed form inclined
towards the cylinder and attached to a small vertical brass rod which with a small
pin forms an anchor or armature opposite an electro-magnet (constructed of two
bobbins wound with wire and of a core of soft iron) attached to a brass carriage
which moves on conducting shafts; the carriage can be turned a quarter of a
revolution on the shaft in order to allow, when required, the removal of the
cylinder.
At the same time that the current passes through the large bobbins, it also
passes through the small bobbins, by which an anchor or armature with the needle
is attracted and then set free by the breaking of the current, thereby communicating
a to and fro movement to the needle.
In addition to this to and fro movement the needle has also a forward movement
when the clock mechanism works in consequence of the carriage being on the one
side drawn by means of a cord and a spring in a barrel and on the other side it is
stopped by a cord, wound on a shaft by means of a vertical pulley.
When the clockwork goes the first described cord is wound up and the second
cord is unwound. When the hand reaches the end of the cylinder and the records
have been made it is necessary in order to make fresh records to bring back the
carriage to the commencement of the cylinder by winding the last named cord on
its shaft which can be turned independently of the shaft of the clockwork and the
return movement of which is prevented by a catch.
As the paper on the cylinder is divided into as many horizontal bands as there
are seconds of time in one revolution, it will be evident that, the rotation of the
cylinder and the to and fro movement of the hand commencing simultaneously;
it follows that the number of bands placed between the first marked records and
the place where the hand recommences its oscillations, or in other words, the
points near the treadles at which the first wheel comes on the bridge and leaves it,
will indicate the number of seconds which the train has taken to pass over the
bridge.
At the same time the number of oscillations produced by the hand or needle on
the paper correspond with the number of wheels which have passed the point of
contact.
The operation of the apparatus is as follows:-
The herein before described contact plates on the bridge are connected by
conducting wires with a battery aud with the bobbins.
The current from the battery is interrupted as many times by the contact plates
of the first treadle as by those of the second treadle on the bridge. At each
pressure of the first wheel on the first treadle placed at the commencement of the
bridge the current, by the contact of the two contact plates passes to No 1, treadle
(not to No 2, treadle) and through the bobbin of the small electro-magnet, then
passes through the other bobbins and returns by the piece to the other pole of the
battery.
During the passage of the current the cores of the bobbins are magnetized and

page_text: consequently the anchors or armatures are simultaneously attracted. The effect of
the attraction of the first anchor or armature is that one of the arms of the lever
is raised, the fly is set free and the clock movement commences to work. The
cylinder turns and the carriage is set in motion moving along its shaft; the
attraction of the anchor or armature causes the hand or needle to oscillate over the
paper on the cylinder. The passage of each wheel over the first treadle imparts
an oscillating motion to the needle or hand; after the passage of the last wheel,
the needle or hand passes along the cylinder until the first wheel reaches the
second treadle when it again commences to oscillate.
After the passage of the last wheel over the second treadle, the needle or hand
drags until the shaft (and consequently the cylinder also) has completed a
revolution, at which moment the pin reverses the small rod, which raises the arm
of the lever placed above, and retains the fly pinion by its pressure on the ebonite
plate in such a manner that the clockwork is stopped. At the same time the
lowering of the other arm of the lever causes the catch in the form of a knife to
fall into the notch of the wheel and the end of the arm is released from the
spring.
The hand or needle which by its movement on the revolving cylinder will
describe a helicoidal line, returns after one revolution of the cylinder to the same
horizontal line forming its point of departure and is ready to commence its
operation for the next train.
It will be evident that, in place of obtaining the records by means of horizontal
bands on the paper, the same result may be obtained by measurement, the circum-
ference of the cylinder being known, and also the number of seconds occupied in a
revolution.
The cylinder should be constructed in such a manner that the number of seconds
required for one revolution should be equal to a certain number of millimeters, so
that by measuring the length of the line marked in millimeters, the number of
seconds will be at once known.
The apparatus to be employed in the station office is enclosed in a case with
glass sides which is locked by a key.
The handle of the drum or barrel should be extended so that the knob should be
outside the case which will enable the attendant to wind up the clockwork several
times daily to insure a regular action of the spring in the barrel.
The barrel and spring may be replaced by a weight whereby a more regular
action of the clockwork would be obtained.
Further an opening (closed by a sliding or hinged lid) should be made in the
upper side of the case above the cylinder in order that the inspector may be able
to mark by means of a hand or needle, the number or letter of the train which
has passed, by which means all danger of removing the lamp black from the paper
or of blurring or staining it will be avoided.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said George Frederick Redfern in the Great Seal Patent Office on the
30th August 1882.
GEORGE FREDERICK REDFERN of the General Patent Office, 4 South Street,
Finsbury, in the county of Middlesex, Patent Agent IMPROVEMENTS IN APPARATUS
"
"
FOR CHECKING AND RECORDING THE SPEED OF TRAINS PASSING OVER RAILWAY
BRIDGES, GRADIENTS, OR OTHER PARTS OF THE PERMANENT WAY A communi-
cation from abroad by Jan Herman Marie Waldorp, of Nymegen, in the Kingdom
of Holland, Civil Engineer.
.
The constantly increasing weight of the loads carried by railway trains, has
latterly caused attention to be directed to the necessity of limiting the speed of
such trains when passing over iron railway bridges, having regard to the security
and the preservation of such bridges, and in some countries regulations have
already been enacted in this direction, as for example in the kingdom of Holland
where the speed at which trains are allowed to pass over long bridges is limited to
thirty kilometers (about eighteen and a half miles) an hour. Now the object of
this invention is to provide mechanism and apparatus for registering this speed.
Such mechanism of which the registering or recording apparatus hereinafter
described constitutes an integral part, should, to be of practical value for the
purpose for which it is intended, combine the following properties:
(1). The mechanism should work automatically without the intervention of the
employé charged with taking off the records as the only duty of this employé
should be to see to the regular working of the mechanism and to prepare the
instrument for receiving the records.
(2). The apparatus for receiving and making the records should be placed within
the immediate reach of the said employé and should by preference be placed in the
office of the station superintendent and it should be enclosed in such a manner
that no other person than he can touch it.
(3). The records should comprise a series of trains passing during a given space
of time, say for example, twenty four hours, without it being necessary for the
employé to touch the apparatus.
(4). The records should be such, if required, as to separately indicate the speed
of the trains at various parts of the bridge, gradient or other part of the permanent
way, as the case may be.
None of the apparatuses at present in use fulfil these combined conditions, they
give inexact results and therefore cannot be relied on.
Some of the said apparatuses indicate the speed (notably the le Boulenge system)
by means of a needle moving over a dial; by observing the space passed over by
the needle the speed of the train is calculated; and the needle has to be brought
back to zero for the next train.
Others (such as those used on the Netherland States Railways) indicate the
progress of the train over the bridge on a band or ribbon of paper by means of a
wheel coated with ink in a similar manner to that by which the Morse apparatus
transmits telegraphic symbols and, to cause the paper band to unroll, the employé
each time a train is due has to put the pendulum of the apparatus in movement
and to stop it when the train has passed. The speed is calculated by measuring
on the band of paper the distance between the point where the wheel commenced
to mark at the entrance of the train and the point at which the wheel commenced
to mark when the train left the bridge.

page_text: PP
common to those employed until now.
The improved mechanism and apparatus may be divided into two distinct parts,
viz:
(A). The mechanism (or bridge apparatus) on the bridge itself consisting of a
certain number of contact points which communicate the passage of the wheels of
the train to;
(B). The apparatus placed in the inspector's office of the nearest station where
the said contacts are recorded.
In the bridge apparatus (which is somewhat similar to those which the Netherland
States Railway has applied to several bridges) the said contact points are applied
either only at both ends of the bridge or at intermediate points according to the
length of the bridge. This apparatus is represented in the views shewn at
Figure 1 of the accompanying drawing but no claim is made to the same taken
separately.
At a short distance above the rail a¹, Figure 1, is placed what may be termed a
treadle constructed of a piece of suitable metal such as steel a, on the end of a
horizontal rod b. When the rod b, turns, the link c, is moved upwards, moving
with it the bar d, thereby placing the contact plates e, e¹, in contact.
From the knobs f, and f¹, pass conducting wires terminating at the station as
hereinafter described. By this means on the pressure of each wheel of the carriage
of a train on the treadle a, the horizontal rod b, turns, the bar d, is raised and the
plate e, is put in contact with the plate e¹. A piece of india rubber h, applied
under the treadle, and the steel wire spiral springs g, g¹, around the bar d, cause
these two pieces to retake their normal position after each wheel has passed, and
thus break the contact between the plates of copper e, and e¹.
The station apparatus is constructed substantially as follows:-
:-
I employ a clock movement operated by a spring and regulated by means of a
Foucault fly pinion (with movable wings) capable of causing a shaft to make each
of its revolutions in the same period of time.
A cylinder follows the rotation of the said shaft and consequently accomplishes
one revolution in the same time; on the said cylinder is marked the space of time
which the train occupies in passing.
An arrangement of mechanism constructed as hereinafter described is employed
to set the clock movement going as soon as the train reaches the bridge and to stop
it after the train has passed.
An apparatus constructed as hereinafter described transmits to the cylinder the
contacts which have taken place on the bridge by the treadles during the passage
of the train over the bridge in such a manner that the distance existing between
the two contacts recorded, taken in connection with the speed of rotation of the
cylinder, will indicate the time the train has been on the bridge between the two
treadles when these are placed at both ends of the bridge.
It will be evident that in this manner by employing several treadle mechanisms
the speed of the train over various parts of the bridge may be checked and
registered.
I will now describe the invention by reference to the accompanying drawing in
which figure 2 is a plan, figure 3, a side elevation partly in section, and figure 4, an
end view partly in section of what I terin the station apparatus, similar letters in
the three figures representing similar parts.
The clock movement is constructed of an arrangement of wheel work contained
in a brass box k, k, and moved by a spring in the barrel T, which is wound up by
means of the handle H. The movement of the clock is regulated by the fly pinion V.
The number of seconds in which it is desired that the shaft A shall make one
revolution is regulated by weighting or lightening the fly pinion. The shaft A
extends outside the box and is provided at one of its ends with a pin P, which
serves to communicate a rotating movement to the cylinder C, C, made of suitable

page_text: sheet metal and fixed on a horizontal shaft D, D, working in two supports S, S,
and carrying at one of its ends a small fork v, into which takes the pin P, in such
a manner that the shaft A, in turning moves the shaft. D, D, and with it the
cylinder C.
:
Each morning before the arrival of the first train the cylinder is covered
with paper coated with white lead blackened over a paraffin lamp as hereinafter
described
The length of the cylinder is regulated according to the number of trains to be
registered on the same paper band and will depend on the speed with which the
marking needle or hand hereinafter described passes over the cylinder.
.
To prepare the cylinder for registering, its shaft is taken from the support and
the cylinder covered with paper, one end of which is coated with gum; it is placed
in a wooden apparatus such as that shewn in figure 5, in the supports of which the
cylinder is turned, a petroleum lamp being placed underneath so that the paper
becomes covered with lampblack.
As soon as the trains which are to be registered have passed, the paper is cut and
removed from the cylinder and plunged in a bath of gum lac and alcohol (figure 6)
for the purpose of fixing the records. The paper is then suspended on the wooden
cross bar of the bath to allow it to drain and dry.
I will now describe the apparatus for starting and stopping the clock movement.
When a train comes on the bridge each wheel, as has been already described,
presses on the treadle a, and causes the two plates e, and e¹, to make contact.
These plates communicate by means of a conducting wire with an electro magnet
consisting of two bobbins E, E, on a core of soft iron over which is placed the
armature or anchor M. An electric current will thus be set up which passing
through the bobbins E, E, and communicating with the soft iron core will attract
the anchor or armature M, the tail B, B, of which turning on the axis a, a, will
thereby be raised. The tail B, B, presses on the underside of one of the arms of
the lever, h, h, h, h, made of the form shewn in figure 4, of the drawing such lever
turning on a small horizontal pivot d, d, The said lever arm is provided with a
small sliding counterweight g, and with a catch m, in the form of a knife and the
end of the lever presses on the side of the spring G which is attached to the
horizontal shaft F, F; the other arm of the lever terminates with a stop button i,
which in the position of the lever shewn in the drawing presses an ebonite
plate p, p, forming part of the vertical shaft of the fly pinion V.
To the same support which carries the small arbor d, d, of the lever is fixed near
the point n, the pivot of the small curved rod 7, 7, the elbow of which presses under
the hereinbefore described arm under the bend of the lever h, h,
The said lever with its accessories has for object the starting and stopping of the
clock work. The parts being in the position shewn in the drawing and the spring
in the barrel being wound up, the movement of the clockwork may be stopped by
pressing the button i against the ebonite plate of the fly; in all cases as soon as
the anchor or armature M, is attracted the tail B, B, thereof raises one of the arms
of the lever which causes the part i, to descend in such a manner that the fly
becomes free and the wheelwork commences to move. The fall of the lever into
its normal position by the breaking of the current and the release of the anchor or
armature is prevented by the pressure of the end of the lever arm against the
spring G.
The stoppage of the clockwork is produced in the following manner; after one
revolution of the shaft A the pin q, being on the wheel of this shaft throws off the
small curved rod or striker l, from which it follows that the movement of this
latter raises one of the arms of the lever near the bend, detaches the other arm from
the spring G, and commences to press the knob i, against the ebonite plate. By
this movement the catch m, is brought against and runs over the periphery of a
small wheel fixed on the shaft A, and almost immediately afterwards it comes over
the notch m¹, and the end of the lever h, h, being now free from the spring, and m,

page_text: above the notch m¹, the weight g, presses the knob i, closely against the ebonite
plate and so stops the clockwork.
The records on the cylinder are produced as follows:-
The shaft A, as hereinbefore described communicates its rotary movement to
the cylinder C, C, against which is placed the needle o, constructed of a small
plate of steel of a pointed form inclined towards the cylinder and attached to a
small vertical brass rod u, u, which with the small pin t, forms an anchor or
armature opposite the electro magnet e, e, (constructed of two bobbins wound with
wire and of a core of soft iron) attached to a brass carriage, f. f. which moves on
the conducting shafts r, r, r², r₁, fixed in the supports O, O; the carriage can be
turned a quarter of a revolution on the shaft r, r, in order to allow, when
required, the removal of the cylinder C, C,
At the same time that the current passes through the large bobbins E, E, it also
passes through the small bobbins e, e, by means of the brass pieces N, N', by
which the anchor or armature u, t, u, with the needle o, is attracted and then set
free by the breaking of the current thereby communicating a to and fro movement
to the needle o,
In addition to this to and fro movement the needle has also a forward move-
ment when the clock mechanism works in consequence of the carriage being on
the one side drawn by means of a cord x, x¹, and a spring in a barrel z, and on the
other side it is stopped by the cord x, x, wound on the shaft 7, by means of the
vertical pulley y,
When the clockwork goes, the cord x1, x¹, is wound up and the cord x, is
unwound, When the hand reaches the end of the cylinder and the records have
been made it is necessary, in order to make fresh records, to bring back the carriage
to the commencement of the cylinder by winding the cord x, on the shaft l, which
can be turned independently of the shaft of the clockwork and the return
movement of which is prevented by a catch.
The cylinder is constructed in such a manner that the number of seconds
required for one revolution should be equal to a full number of millimeters so that
by measuring the distance between the first marked records and the place where
the hand recommences its oscillations, or in other words, the points near the
treadles at which the first wheel comes on the bridge and leaves it, will indicate
the number of seconds which the train has taken to pass over the bridge.
At the same time the number of oscillations produced by the hand or needle on
the paper corresponds with the number of wheels which have passed the point of
contact.
The operation of the apparatus is as follows:-
The herein before described contact plates on the bridge are connected by the
conducting wires with the battery Z, and with the bobbins E, E, and e, e, in the
manner represented in the drawing.
Supposing the parts to be in the position shewn in the drawing. The current
from the battery is interrupted as many times by the contact plates of the first
treadle as by those of the second treadle on the bridge, at each pressure of the
first wheel on the first treadlo placed at the commencement of the bridge the
current by the contact of the two contact plates passes to No 1, treadle (not to
No 2, treadle) reaches the piece N', whence it passes through the bobbin of the
small electro magnet e, e, then passes through those marked E, E, and returns by
the piece N, to the other pole of the battery.
During the passage of the current the cores of the bobbins E, E, and e, e, are
magnetised and consequently the anchors or armatures M, M, and u, t, u, (the pin)
are simultaneously attracted. The effect of the attraction of the first anchor or
armature is that one of the arms of the lever is raised, the fly V, is set free and the
clock movement commences to work. The cylinder C, C, turns and the carriage
ff, is set in motion, moving along the shaft r, r,; the attraction of the anchor or
armature u, t, u, causes the hand or needle to oscillate over the paper on the
cylinder. The passage of each wheel over the first treadle imparts an oscillating

page_text: motion to the needle or hand; after the passage of the last wheel, the needle or
hand passes along the cylinder until the first wheel reaches the second treadle
when it again commences to oscillate.
After the passage of the last wheel over the second treadle the needle or hand
drags until the shaft A, (and consequently the cylinder also) has completed a
revolution at which moment the pin q, reverses the small rod 7, which raises the
arm of the lever placed above, and commences to retain the fly pinion by its
pressure on the ebonite plate. At the same time the lowering of the other arm of
the lever causes the end of the arm to be released from the spring G but the
catch m, being still on the circumference of the small wheel the clockwork is not
stopped but slackened, the next moment however, the catch m, comes above the
notch m' and the weight g, brings the full pressure of the knob i, against the ebonite
plate of the fly pinion and the clockwork is stopped.
The hand or needle which by its movement on the revolving cylinder will
describe a helicoidal line, returns after one revolution of the cylinder to the same
horizontal line forming its point of departure and is ready to commence its
operation for the next train.
As the cylinder is constructed in such a manner that the number of seconds
required for one revolution is equal to a full number of millimeters, it will be
evident that by measuring the length of the line marked, in millimeters, the
number of seconds will be at once known.
The apparatus to be employed in the station office is enclosed in a case having
glass sides and locked by a key.
The handle of the drum or barrel T, should be extended so that the knob should
be outside the case which will enable the attendant to wind up the clockwork
twice a day in order to insure a regular action of the spring in the barrel.
The barrel and spring may be replaced by a weight whereby a more regular
action of the clockwork would perhaps be obtained.
An opening (closed by a sliding or hinged lid) should be made in the upper
side of the case above the cylinder in order that the inspector may be able to mark
by means of a hand or needle, the number or letter of the train which has passed,
by which means all danger of removing the lamp black from the paper or of
blurring or staining it will be avoided.
Although the invention has been described as applied to a railway bridge it is
evident that it is equally applicable to gradients and other parts of the permanent
way.
Having now described the nature of the said invention and the manner of
performing the same, I wish it to be understood that what is claimed and intended
to be protected by the herein in part recited Letters Patent is :-
Firstly. The general arrangement and construction of the improved apparatus
for checking and recording the speed of trains passing over railway bridges,
gradients, and other parts of the permanent way, arranged and operating
substantially as hereinbefore described and represented in the accompanying
drawing.
Secondly. The use of a treadle mechanism such as that herein described at both
ends of a railway bridge (or other position) in combination with the recording
mechanism at the station whereby each wheel of the carriages of a train which
passes over the said treadle mechanism causes a contact to be made so as to close
an electric current in communication with the said recording mechanism at the
station substantially in the manner and for the purposes herein before described and
represented in the accompanying drawing.
Thirdly. The method herein described of giving a regular motion to a shaft, by
means of clock work mechanism driven by a spring and regulated by a fly,
substantially as and for the purposes herein before described and represented in the
accompanying drawing.
Fourthly. The cylinder C, covered with prepared paper and receiving a revolving
movement from and corresponding with the shaft A, the said cylinder serving to

page_text: record the time taken by the train in passing over the bridge, substantially in the
manner herein before described and represented in the accompanying drawing.
Fifthly. The construction and employment of the mechanism for starting and
stopping the clock work, respectively, on the train entering and leaving the bridge
substantially as and for the purposes herein before described and represented in the
accompanying drawing,
Sixthly. The hand or needle o, resting on the rotating cylinder C and moving
along it and having a to and fro movement communicated to it by the attraction
of an electro magnet at each contact of the treadle mechanism, whereby the
passage of the wheels of the carriages of a train over the ends of a bridge is
recorded on the prepared paper on the cylinder C and whereby the distance
between the first and last recorded contacts at either end of the bridge taken in
relation to the rotary speed of the cylinder will give the time taken by the train
in passing over the bridge substantially as hereinbefore described and represented
in the accompanying drawing.
In witness whereof I the said George Frederick Redfern have hereunto set
my hand and seal this twenty ninth day of August in the year of our
Lord one thousand eight hundred and eighty two.
G. F. REDFERN. (L.S.)