A SELF-ACTING MECHANISM FOR INDICATING THE TIME BETWEEN THE PASSING OF Two ENGINES OR TRAINS ON THE SAME LINE OF RAILWAY
Year: 1871

page_text: LETTERS PATENT to Henry William Harman, of Manchester, in the
County of Lancaster, Civil Engineer, and William Henry Jones
Mills, of Mexbrough, in the County of York, Linen Draper, for
the Invention of "A SELF-ACTING MECHANISM FOR INDICATING THE TIME
BETWEEN THE PASSING OF Two ENGINES OR TRAINS ON THE SAME LINE
OF RAILWAY."
Sealed the 7th October 1871, and dated the 27th April 1871.
PROVISIONAL SPECIFICATION left by the said Henry William Harman
and William Henry Jones Mills at the Office of the Commissioners
of Patents, with their Petition, on the 27th April 1871.
We, HENRY WILLIAM HARMAN, of Manchester, in the County of
Lancaster, Civil Engineer, and WILLIAM HENRY JONES MILLS, of Mex-
brough, in the County of York, Linen Draper, do hereby declare the
nature of the said Invention for "A SELF-ACTING MECHANISM FOR INDICATING
THE TIME BETWEEN THE PASSING OF TWO ENGINES OR TRAINS ON THE SAME LINE
OF RAILWAY," to be as follows:-
This Invention consists in a means whereby a locomotive engine or
other moving body passing over the rails of a railway can be made

page_text: to indicate to a subsequent moving body passing over the same rails in
the same direction the interval of time that has elapsed between the two;
so that in the case of an ordinary railway train, the driver and guard
would know when the previous train had passed within the limits of
half an hour, or other period of time which would be considered a
sufficient interval to ensure safety.
A convenient mode of performing our Invention is as follows:-The
mechanism consists of a dial plate and index finger; the dial plate is
placed near the line of rails, between or near which is a tumbler lever,
actuated by the engine or train. To the axle of the tumbler lever ]
is fixed a stud acting on a weighted lever, and this weighted lever is
connected to the index finger. By this arrangement the first train that
passes depresses the tumbler lever, and actuates the parts above referred to
to bring the index finger to zero. The descent of the weighted lever
when liberated from a catch causes causes the index finger to pass over 1
the dial, which indicates time by minutes, so that when the next engine
or train passes the driver or guard can see how long it is since the previous
train had passed; the action of the second train on the tumbler lever
again brings the index finger back to zero on the dial; the weighted
lever again commences its descent, and so puts the parts in position
for indicating the time before the next train passes.
Our Invention may be modified by the use of clockwork, or of a
column of mercury, or other fluid, or sand acting through suitable levers
and connections on the index finger of the dial plate.
SPECIFICATION in pursuance of the conditions of the Letters Patent, 25
filed by the said Henry William Harman and William Henry
Jones Mills in the Great Seal Patent Office on the 27th October
1871.
TO ALL TO WHOM THESE PRESENTS SHALL COME, we, HENRY
WILLIAM HARMAN, of Manchester, in the County of Lancaster, Civil 30
Engineer, and WILLIAM HENRY JONES MILLS, of Mexbrough, in the
County of York, Linen Draper, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Twenty-seventh day of April, in the
year of our Lord One thousand eight hundred and seventy-one, in the 35

page_text: thirty-fourth year of Her reign, did, for Herself, Her heirs and successors,
give and grant unto us, the said Henry William Harman and William
Henry Jones Mills, Her special licence that wc, the said Henry William
Harman and William Henry Jones Mills, our exccutors, administrators,
and assigns, or such others as we, the said Henry William Harman
and William Henry Jones Mills, our executors, administrators, and
assigns, should at any time agree with, and no others, from time to
time and at all times thereafter 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 "A SELF-ACTING MECHANISM FOR INDICATING
THE TIME BETWEEN THE PASSING OF Two ENGINES OR TRAINS ON THE SAME LINE
OF RAILWAY," upon the condition (amongst others) that we, the said
Henry William Harman and William Henry Jones Mills, our exccutors
or administrators, by an instrument in writing under our, or their, or
one of our or their hands and seals, should particularly 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 we, the said Henry William Harman and
William Henry Jones Mills, do hereby declare the nature of our said
Invention, and in what manner the same is to be performed, to be par-
ticularly described and ascertained in and by the following statement
(that is to say) :—
This Invention consists in a self-acting combination of machinery,
whereby a locomotive engine or other moving body passing over the
rails of a railway can be made to indicate to the driver or guard of a
subsequent locomotive engine or other moving body passing over the
same rails, in the same direction, the interval of time that has elapsed
between the two; so that in the case of an ordinary railway train the
driver and guard would know when the previous train had passed within
the limits of half an hour, or other period of time which would be
considered a sufficient interval to ensure safety.
And in order that our Invention may be fully understood and readily
carried into operation, we will proceed to describe the accompanying
Sheet of Drawings, reference being had to the figures and letters marked
thereon.

page_text: Fig. 1 is an elevation; Fig. 2 is a plan; Fig. 3, another elevation;
and Fig. 4, a section of the self-acting mechanism for indicating the
time between the passing of two engines or trains on the same line of
railway.
a, a, are the rails supported in chairs laid on sleepers, as shewn in
Fig. 3, or in any other convenient manner; b is an axle; and c, c, the
wheels forming part of the locomotive engine, tender, truck, or carriage
of a railway train; and d, d, are rims or flanges projecting from or fixed
to or forming part of the driving wheels of a locomotive engine, or fixed
to the axle box thereof. If desirable such rim or flange can be fixed to
any or all the wheels of any locomotive engine, tender, truck, or carriage.
The object of having a rim or flange to both of the driving wheels or
pair of other wheels is to provide for the reversing of the engine
or carriage. Near to the line of rails and at any convenient position,
either at the station or at any suitable distance from the station, is
erected a turret e with a clock at the top; this clock is provided with
an index finger or minute hand, the range of which is limited to thirty
minutes, or other period of time. Behind the dial plate of the clock
is a disc g, shewn best in Fig. 4; this disc is loose on a boss concentric
with the axle of the minute hand f, and to it is fixed a small drum
containing a coiled spring. To the drum is suspended the weight i,
which is heavy enough to overcoine the spring in the drum h. To the
disc g is also fixed the stud j, for acting when required on the minute
hand f, and for bringing it against the stop k projecting from the dial
face or other fixture. To the axle of the hour hand of the clock is fixed
a mitre pinion, gearing into and driving a similar pinion on the upright
shaft m, at the lower end of which is a finger n with a sharp point;
below this is the registering or tell-tale dial o, made of cardboard or
other suitable material, which is fixed in a slot or groove, or secured
by pins or otherwise on a circular plate p; this plate has a spindle
which is capable of moving up and down in a socket, so that the paper
dial may be brought against and marked by the pointer of the finger n.
The clockwork is brought into communication with the passing train by
means of the double inclined spring r, one end of which is fixed to a
sleeper or other suitable fixture. To the under side of the spring”
is jointed the upper end of the link 8, the lower end of which is jointed
to one end of the lever t, which vibrates on the stud f. To the other
end of the lever is jointed the lower end of the rod u, which is
supported in sockets in the turret e. The upper end of the rod u has

page_text: a cross licad, which acts when required on the weight and on the
spindle of the plate p.
The mode of operation is as follows, and I wish to remark here that
the turret e is set at an angle to the line of rails, so that the driver of
a train advancing in the direction of the arrow in Fig. 2 may see the
dial of the clock as the train approaches it-The minute hand ƒ is
shown at about twenty minutes past the hour, thereby indicating that
the same time has elapsed since the last train passed. As soon as the
flange d of the advancing train or vehicle depresses the spring",
the outer end of the levert is raised, and the cross head on the rod u
lifts the plate p to press the dial o against the point in the finger n, to
record the time of the passing train on the said dial, at the same time
the weight is raised to liberate the disc g; the spring in the drum h
now comes into operation and moves the disc g half round in the
direction of the arrow in Fig. 1; and in so moving the projection j,
acting on the end of the minute hand f, carries it back to the vertical
position, as shewn by dotted lines in Fig. 1, where it is stopped by the
projection . As soon as the flange d has passed beyond the spring »
it regains its former position, and the cross head on the rod u being
withdrawn from under the plate p allows it to drop clear of the
pointer n, the weight i being also set at liberty acting on the cord, strap,
or chain wound on the drum h, turns the disc g half round, and brings
the projection ; to the under side of the dial, as shewn in Fig. 1. The
minute hand fis now again acted upon by the clockwork, and continues
to indicate the minutes until another train passes, when the same
operations are performed in the same manner. If no train should
pass for more than half an hour, or other fixed period of time, the
minute hand would remain in contact with the projection ; while
the clock continues to operate. By means of this mechanism the finger
or hand indicates to the driver, guard, or other person on a train the
time that has elapsed since the previous train has passed, and the
registering dial indicates the number of trains that have passed in
twelve hours, and also the time at which each train passed. The
registering dial o must be removed from the turrets by some trustworthy
official who has the key of the turret door, which must be opened to
remove the registered dial, and to replace it by a blank dial; and I
prefer to connect the lock of the said door to the clockwork in such
wise that the door cannot be opened until the clock is wound up.

page_text: .
In order that the custodian or official may regulate the movements
of the clock, a small dial with hour and minute hands is placed on the
reverse or opposite side of the index dial before named, as shewn in
Fig. 3. The various turrets along a line of rails may be connected
by wires or rods, so that when a train arrives at one turret it depresses
the spring ", which operation registers time and moves the index finger
to zero, as before described. The index finger is kept in that position
by a catch until the train arrives at and depresses the spring at the next
turret, which action releases the catch at the first turret when the disc
falls and the finger moves, thereby shewing that the line is clear between
the two turrets, and also what time has elapsed since the train left the
first turret. It is evident that the registering dial o may be made
to indicate the passage of trains in twenty-four instead of twelve hours,
and that the details of the mechanism may be considerably modified.
We would also remark that instead of the clockwork described for
moving the finger f, a column of mercury or other fluid or sand acting
through suitable levers and connections may be employed.
Having thus stated the nature of our Invention, and described a
convenient manner of performing the same, we declare that we claim
the self-acting mechanism shewn and described, or any modification
thereof, for indicating the time between the passing of two engines or
trains on the same line of railway, and for registering the same.
In witness whereof, I, the said William Henry Jones Mills, for
myself, and on behalf of the said Henry William Harman, have
hereto set my hand and seal, this Twenty-fifth day of October,
One thousand cight hundred and seventy-one.