Improvements in Electric Apparatus for Signalling on Railways.
Year: 1894

page_text: Date of Application, 12th Jan., 1894
Complete Specification Left, 12th Oc'., 1894-Accepted, 17th Nov., 1894
PROVISIONAL SPECIFICATION.
Improvements in Electric Apparatus for Signalling on Railways.
I, ROBERT STUART HAMPSON, of Godley Junction, in the County of Chester,
Telegraph Superintendent to the Manchester Sheffield and Lincolnshire Railway
Company, do hereby declare the nature of this invention to be as follows:-
My invention relates to what are known as three wire Block Telegraph
instruments, and particularly to permissive Block Telegraph instruments which
allow two or more trains to be in one section at the same time and the chief
object of my invention is to improve and simplify such instruments and reduce
their cost.
In carrying my improvements into effect I employ a disc quadrant or drum
with the usual words or marks which indicate the three positions "Line blocked,"
"Line clear," "Train on line," as well as (in the case of a permissive block
instrument) a series of numbers from say 1 to 4 or more or less as required,
indicating the number of trains. This indicator is suitably mounted to turn or
slide so as to bring the required indication opposite the opening in the front of the
instrument case, and is actuated by means of suitable connections from a slide
fitted preferably at or near the bottom of the instrument case.
This slide has a knob or handle which projects through the front of the casing
for convenience in working by the signalman and the slide has a series of notches to
receive a spring catch or locking lever which is conveniently placed to engage
each notch in turn and is operated by a plunger or key from the outside of the
instrument case. There is also a spring catch preferably placed below the slide
which holds the locking lever clear of the notches until the said catch is released or
withdrawn by the movement of the slide. The electric circuit is closed or broken
as required by means of three spring or other contact makers which either rest
upon an insulating piece or the metal slide itself and so break or make circuit
according to the position occupied by the slide.
In operation if the instrument is constructed so that the slide is locked by the
locking lever when the indicator shows "Line blocked"" (which may or may not be
the case) then the signalman before pulling out the slide must release it by using
the plunger or key. The locking lever is then held out of the notch by the spring
catch and the signalman can draw out the slide to the "Line clear" position and
in doing so this movement i.e. "Line clear" is automatically signalled to the other
box by the change in position of the electric contact makers caused by the
movement of the slide. The slide is locked in its new position by the locking
lever engaging the corresponding notch, the locking lever having been previously
released from the spring catch by the movement of the slide from the "Line
blocked" to the "Line clear" position. Before the signalman can pull out the
slide to the "Train on line" position he must again use the plunger or key to
withdraw the locking lever and unlock the slide and by then pulling out the
slide the "Train on line" position is indicated in his cabin and also signalled
electrically and automatically to the next cabin, the slide being locked in the
"Train on line position until the locking lever is withdrawn by using the
plunger or key as before described. In an absolute block instrument the slide
would now have reached the limit of its withdrawal but in a permissive block
instrument the further withdrawal of the slide which is essential does not effect
any change in the electric current which remains closed at the "Train on line
position but merely serves to change the mechanical indication of the number of
the train or trains at the forwarding end of the section
"
"

page_text: The movement of the slide in the opposite direction is effected by reversing the
series of operations described.
Dated this 11th dow of January 1894.
H. B. BARLOW & GILLETT,
Agents for Applicant.
COMPLETE SPECIFICATION.
Improvements in Electric Apparatus for Signalling on Railways.
I, ROBERT STUART HAMPSON, of Godley Junction, in the County of Chester,
Telegraph Superintendent to the Manchester Sheffield and Lincolnshire Railway
Company, do hereby declare the nature of this invention and in what manner the
same is to be performed, to be particularly described and ascertained in and by the
following statement :—
My invention relates to what are known as three wire Block Telegraph
instruments, and particularly to permissive Block Telegraph instruments which
allow two or more trains to be in one section at the same time and the chief
object of my invention is to improve and simplify such instruments and reduce
their cost.
In carrying my improvements into effect I employ a disc quadrant or drum with
the usual words or marks which indicate the three positions, "Line blocked,"
"Line clear," "Train on line," as well as (in the case of a permissive block
instrument) a series of numbers for say 1 to 4 or more or less as required,
indicating the number of trains. This indicator is suitably mounted to turn or
slide so as to bring the required indication opposite the opening in the front of the
instrument case, and is actuated by means of suitable connections from a slide
fitted preferably at or near the bottom of the instrument case.
This slide has a knob or handle which projects through the front of the casing
for convenience in working by the signalman and the slide has a series of notches
to receive a spring catch or locking lever which is conveniently placed to engage
each notch in turn and is operated by a plunger or key from the outside of the
instrument case. There is also a spring catch preferably placed below the slide
which holds the locking lever clear of the notches until the said catch is released
or withdrawn by the movement of the slide. The electric circuit is closed or
broken as required by means of three spring or other contact makers according to
the position occupied by the slide.
And in order that my invention may be fully understood and readily carried into
effect I will describe the accompanying three sheets of drawings reference being
had to the figures and letters marked thereon.
Figure 1 is an elevation of a permissive block telegraph instrument to which
my improvements are applied.
Fig. 2 is a sectional plan of Fig. 1.
Fig. 3 is a front and Fig. 4 a back elevation with the cover and parts of the
casing removed.
Fig. 34 is a detail of Fig. 3, showing the parts in a different position, and
Fig. 5 is a plan illustrating the electrical connections with the slide.
In these views, a designates the stand or frame of the instrument, b the
detachable cover, and c the quadrant with the words "Line blocked," "Line
clear," "Train on line 1," "Train on line 2," etc., up to 4. This quadrant or
indicator c is mounted on a spindle c' supported in a frame secured to the front
part of the stand a; on the spindle c' is fixed an arm or lever d which engages a
diagonal slot e' in a slide e fitted in the lower portion of the stand a below the
indicator c.
The slide e is drawn out or pushed in by means of a handle e² and along one side
the slide has a series of eix notches numbered e' to e' respectively which correspond

page_text: to the six indications marked on the indicator c. Near the side of the slide e is a
spring catch leverf which is conveniently placed to engage each notch in turn and
so lock the slide e and indicator c. The spring catch lever is normally held in a
notch in the slide by means of its spring. It is withdrawn from the slide e by
means of a plunger or key lever g which projects through the front of the instrument
case and is provided with a knob or handle g²; at the other end the lever g lies
under the arm of a spring lever h which has at its other end a claw ' which is
held normally above and clear of the notches in the slide by means of the spring i.
The spring catch lever and the claw lever h are both shown fulcrumed on the
same stud although this is only a convenient arrangement and is not essential.
To withdraw the spring catch leverf from a notch in the slide e the key lever 9 is
depressed thereby raising the arm of the lever h and by the claw /* forcing back
the spring catch leverf which is then latched hack in position clear of the slide e
by a spring catch k placed below the slide. The spring catch is tripped and the
spring catch lever is released and drawn forward by its spring into a notch
whenever the slide e is moved either forward or backward by means of a rack or
series of studs eo fixed on the under side of the slide e, these studs depressing the
spring catch and allowing the spring catch leverf to come over it whenever the
slide is moved.
The electric circuit is closed or broken as required by means of the three spring
contact makers m² m² m² which, according to the position occupied by the slide,
either rest upon an insulating piece n or upon copper strips o and o¹ secured to the
slide and so make or break the electric circuit. This arrangement is illustrated
by Fig. 5 as well as the arrangement of the connecting wires which requires no
description as it is that customary in block telegraph instruments.
In order to lock the indicator c temporarily in each of its positions I fix a spring
piece p to a bracket on the back of the instrument stand a.
This spring piece p
engages in turn a series of notches s' in a plate s fixed at the back of the indicator c,
the series of notches & corresponding to the series of indications "Line blocked,"
'Line clear," etc., marked on the indicator which is actuated when the slide is
drawn out or pushed in by means of the diagonal slot e¹ and arm or lever d already
described.
66
In operation if the instrument is constructed so that the slide e is locked by the
locking leverf when the indicator c shows "Line blocked" (which is the case with
the instrument illustrated in the drawings but is not essential for the purposes of
my invention) then the signalman before pulling out the slide e must release it by
using the key lever g as described. When this has been done the locking lever fis
held out of the notch e by the spring catch as shown in Fig. 34, and the
signalman can draw out the slide e to the next or Line clear" position, and in
doing so this movement i.e. "Line clear" is electrically and automatically signalled
to the other box by the change in position of the electric contact makers m³ m³ m³
caused by the movement of the slide e.
The slide e is locked in its new position ("Line clear") by the locking lever f
engaging the corresponding notch e, the locking lever having been previously
released by and from the spring catch k by the studded rack 10 on the under side
of the slide as the latter was moved from the "Line blocked" to the "Line
clear" position. Before the signalman can pull out the slide e to the "Train
on line" position he must again use the key lever g to withdraw the locking
lever from the notch e and unlock the slide and by then pulling out the slide
the "Train on line" position is indicated in his cabin and also signalled electrically
and automatically to the next cabin, the slide e also is locked automatically in the
"Train on line" position by the locking leverf engaging the notch e and remains
locked until the locking lever is withdrawn by using the key lever g as before
described.
In an absolute block instrument the slide e would now have reached the limit
of its withdrawal ; but in a permissive block instrument as illustrated, the further
withdrawal of the slide which is essential does not effect any change in the electric

page_text: current which remains closed at the "Train on line" position; but merely serves
to change the mechanical indication of the number of the train or trains at the
forwarding end of the section.
The movement of the slide e in the opposite direction is effected by reversing the
series of operations described.
In place of the diagonal slot e¹ in the slide and the arm d on the spindle c¹, a rack
and pinion or other suitable mechanism might be employed for actuating the
indicator at each movement of the slide.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed I declare that what I
claim is :-
1. Actuating the indicator of a three wire block telegraph instrument by means
of a slide which is fitted in the instrument case and is combined with contact
makers and an electric circuit in such manner as to automatically signal each
movement to the next cabin and further is by suitable mechanism automatically
locked in each of the positions denoted by the indicator until released by a key
lever or equivalent device actuated by the signalman prior to every movement, all
substantially as herein set forth.
2. The combination, in a three wire block telegraph instrument, of a movable
indicator with connections to a slide fitted in said instrument case, a spring locking
lever placed to engage a series of notches in the slide and lock the latter in the
position corresponding to that denoted by the indicator, a key lever for actuating
a spring claw lever or equivalent device for withdrawing the locking lever from
the slide, a spring catch which serves to hold the locking lever out of the notch
until released by the movement of the slide and electric contact makers which make
or break an electric circuit according to the position occupied by the slide, all
substantially as and for the purposes herein set forth.
3. The combination with the indicator and the notched slide e, of the spring
locking lever f, the key lever g, the spring claw lever h, and the spring catch k,
all arranged and operating substantially as and for the purposes herein set forth.
4. The combination with the indicator, and the notched plate thereon, of the
spring catch p substantially as and for the purposes specified.
5. The general construction combination and arrangement of parts embodying
my improvements in electric apparatus for signalling on railways all substantially
as and for the purposes herein described and as illustrated by the accompanying
drawings.
Dated this 11th der of October 1801
H. B. BARLOW & GILLETT,
17, St. Ann's Square, Manchester, Agents for Applicant.