Improved Method of and Apparatus connected with Block Signalling on Railways.
Year: 1891

page_text: Date of Application, 10th Apr., 1891
Complete Specification Left, 11th Jan., 1892-Accepted, 12th Mar., 1892
PROVISIONAL SPECIFICATION.
Improved Method of and Apparatus connected with Block Signalling
on Railways.
I, RICHARD ROBERT HARPER, of Sash Court, Wilson Street, Finsbury, in the
County of London, Electrical Engineer, do hereby declare the nature of this
invention to be as follows:-
This invention relates to a novel method, or apparatus by which indicator discs
of electric recording and receiving instruments can be operated by a turn button,
or handle, moveable to the right and to the left at the wish of the operator, said
movement being circularwise for full or continuous rotation in one direction or in
the other, thereby giving the operator full command over the instrument instead of
a limited action in one, or other directions only.
By my improved method of and apparatus for block signalling on railways, I
obtain three signals on a one wire system by the use of certain means of joining up
the electrical connections.
I provide an additional or third set of commutator springs to single wire block
signalling telegraph instruments, which springs are in connection with a set of
resistance coils, or shunt fitted in the interior of the instrument from which coils,
the wire is carried to the coils of the electro-magnet, the amount of resistance being
arranged or regulated, so that the current shall neutralise, or overcome the residual
magnetism in the electro-magnets, thus liberating the armature and allowing the
needle to fall to a vertical position by gravity.
The three sets of commutator springs are operated from a single push or plunger,
which when pushed in, presses against one of the three sets of commutator
springs.
The position of the levers is altered to correspond, or be opposite to one or other
of the sets of commutator springs by being mounted on a revolving plate or disc
provided with cogs mounted on the axis or spindle carried to the front of the
instrument where it terminates in a milled head which is turned by the operator,
the said disc being held firmly by a roller wheel bearing against the cogs by the
aid of a spring. The disc has three indices or indicators marked on it which may
be the words "Line clear," "Train on line," and "Train off but section blocked,'
only one of the indicators being visible at one time.
1
When the disc is turned to the position showing "Line clear," one spring lever
is opposite, say the right hand set of commutator springs; when the indicating disc
is turned to "Train on line" another of the levers comes to a position opposite say,
the centre set of commutator springs; and when the indicator is moved round to
"Train off but section blocked," a third lever has moved to a position opposite
the additional or third set of commutator springs which put the resistance coils, or
shunt into the circuit, thus causing the neutralization of the residual electro-
magnetism and liberating the indicator needle on the dial plate of his own and of
the distant station, thus allowing the needle, or other index to assume a vertical
position indicating "Section blocked."
The call bell is operated on the same circuit as that on which the last signal was
sent.

page_text: COMPLETE SPECIFICATION.
Improved Method of and Apparatus connected with Block Signalling
on Railways.
I RICHARD ROBERT HARPER of Sash Court, Wilson Street, Finsbury, in the
County of London, Electrical Engineer, do hereby declare the nature of this inven-
tion and in what manner the same is to be performed, to be particularly described
and ascertained in and by the following statement :-
This invention relates to a novel method or apparatus by which indicator discs of
clectric recording and receiving instruments can be operated by a turn button or
handle movable to the right and to the left at the wish of the operator, said move-
ment being circularwise for full or continuous rotation in one direction or the other
thereby giving the operator full command over the instrument instead of a limited
action in one or other direction only.
The invention is based upon that previously patented by me on the 16th January
1885 but which in consequence of the limited action of the handle rendered the
working somewhat unsatisfactory and often unreliable.
By the improved method of and apparatus for block signalling on railways
described in the Specification of the Patent above referred to I obtain three signals
on a one wire system by the use of certain means of joining up the electrical con-
nections and in which is provided an additional or third set of commutator springs to
single wire block signalling telegraph instruments, which springs are in connection
with a set of resistance coils or shunt fitted in the interior of the instrument, from
which coils the wire is carried to the coils of the electro magnet, the amount of
resistance being arranged or regulated so that the current shall neutralise or
overcome the residual magnetism in the electro magnets thus liberating the
armature and allowing the needle to fall to a vertical position by gravity.
I arranged that the three sets of commutator springs are operated from a single
push or plunger which when pushed in presses against one of the three sets of
.commutator springs.
Now according to my present invention the position of the levers is altered to
correspond or be opposite to one or other of the sets of commutator springs by being
mounted on a revolving plate or disc provided with cogs mounted on the axis or
'spindle carried to the front of the instrument where it terminates in a milled head
which is turned by the operator said disc being held firmly by a roller wheel
bearing against the cogs by the aid of a spring. The disc has three indices or
indications marked on it which may be the words "Line clear" "Train on line
.and Train off but section blocked "only one of the indications being visible at
one time through a sight hole.
"
In order that my invention may be clearly understood I have appended
"the accompanying two sheets of drawings illustrating my improvement and in
which
Figure 1 Sheet 1 is a side sectional view of the door of the instrument it being
understood that all the other parts of the apparatus remain as described and shown
in
my
Patent No. 640 of 1885.
Figure 2 is a back view.
Figure 3 Sheet 2 a front view and Figure 4 a sectional perspective view shewing
more clearly the particular method of holding the dial in its position.
Referring to Figures 1, 2 and 4 A is the disc or dial, which has affixed to
or marked upon it the words "All clear" "Train on line" and "Train off but
section blocked." B is the revolving plate. C. D. E are the cogs. F the
roller wheel bearing against the cogs C. D. E under the action of spring G
His the axis, 1 the milled head or knob for operating the dial. J. K. L are
the three spring levers (for operating the commutators) affixed to the disc B
screwed upon the cogs C. D. E and revolving with the dial or disc A. Each

page_text: lever as the disc B is revolved comes in front of and is operated by the pusher N
the points J, K, L' of the spring levers J. K. L being so arranged as to operate
a separate commutator to send a message at the other end of the line similar to
that visible through the hole P.
When the disc A is turned to the position showing "All clear" one spring
lever J is opposite say the right hand set of commutator springs, shown and
referred to in my Patent No. 640 of 1885, when the indicating disc is turned to
Train on line "another of the levers K come to a position opposite say the centre
set of commutator springs and when the indicator is moved round to "Train off but
section blocked a third lever L has moved to a position opposite the additional
or third set of commutator springs which put the resistance coils or shunt into
circuit thus causing the neutralization of the residual electro magnetism and
liberating the indicator needle on the dial plate of his own and of the distant
station and allowing the needle or other index to assume a vertical position indicating
*Section blocked."
The call bell is operated on the same circuit as that on which the last signal
was sent.
Having now particularly described and ascertained the nature of this inven-
tion and in what manner the same is to be performed I declare that what I
claim is :-
In connection with block signalling apparatus for railways, the employment
of a plate or disc to be completely revolved in either direction to bring the
required indicator into view in combination with a push button for acting against
commutator springs, the plate being fixedly held, as set forth and substantially as
shown by the annexed drawings.
This 9th day of January 1891.
H. GARDNER,
Patent Agent, 166, Fleet Street, London,
Agent for the said R. R. Harper.