Improvements in Electrical Lock and Block Apparatus for Railway Points and Signals.
Year: 1893

page_text: Date of Application, 25th Apr., 1893
Complete Specification Left, 15th Jan., 1894-Accepted, 17th Feb., 1894
. PROVISIONAL SPECIFICATION.
Improvements in Electrical Lock and Block Apparatus for Railway
Points and Signals.
I, EDWARD TYER, of Ashwin Street, Dalston, in the County of London,
Electrical Engineer, do hereby declare the nature of this invention to be as
follows:-
In my Specification No. 2907 of 1869 I described electrical apparatus applied to
railway point and signal levers in such a manner that a signalman at a distance
could lock or unlock those levers, according as the section of the line with which
he had to do was occupied or unoccupied.
My present invention relates to apparatus for a like purpose, which is of the
following description.
On the lever which is to be locked or unlocked I fix a casing, within which
there is an iron pawl hanging immediately over a shoulder of the spring catch rod
of the lever and operating as a stop preventing that catch rod from being raised
and consequently holding the lever locked. The casing containing this pawl has
two iron studs projecting from it towards the poles of an electromagnet fixed within
a casing near the lever."
When an electrical current from a distant station, either directly or by a polarised
relay, excites this electromagnet, the studs, being magnetised by induction, attract
the iron pawl moving it so that it no longer is over the shoulder of the catch rod,
which is thus released, leaving the main lever free to be moved.
In this position the pawl is held by a loaded bell crank within the casing, but
when the main lever is pulled over, the momentum of this bell crank causes it to
take such a position that the pawl escapes it, and when the main lever is again
moved back, the pawl again takes the locking position.
In case of the main lever being forcibly driven against the electromagnet, I
provide this with a spring allowing it to yield.
The casing containing the pawl may be provided with a small spring plunger
which, when the pawl is attracted, is thrust forward making an electrical contact
by which a signal is operated shewing that the main lever is unlocked.
Dated this 25th day of April 1893.
ABEL & IMRAY,
Agents for the Applicant.
COMPLETE SPECIFICATION.
Improvements in Electrical Lock and Block Apparatus for Railway
Points and Signals.
I, EDWARD TYER, of Ashwin Street, Dalston, in the County of London,
Electrical Engineer, 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 :-
In my Specification No. 2907 of 1869 I described electrical apparatus applied to
railway point and signal levers in such manner that a signalman at a distance could
lock or unlock those levers, according as the section of the line with which he had
to do was occupied or unoccupied.
My present invention relates to apparatus for a like purpose, a side view of
D

page_text: which (with covers removed) is shewn by Fig. 1 of the accompanying drawings.
On the lever L which is to be locked or unlocked I fix a casing A within which
there is an iron pawl B hanging immediately over the end of a bar C jointed to
the spring catch rod R of the lever and operating as a stop preventing that catch
rod from being raised out of the notch of the quadrant Q and consequently holding
the lever L locked. The casing A. containing the pawl B has two iron studs D D
projecting from it towards the sliding cores F of an electromagnet G which is fixed
within a casing near the lever L. When an electrical current from a distant
station either directly or by a polarised relay excites the electromagnet G the
studs D, being magnetised by induction from the adjacent cores F of the magnet,
attract the iron pawl B moving it so that it no longer is over the bar C, and the
catch rod R can then be drawn up to allow the main lever L to be moved.
In case of the main lever L being forcibly driven against the electromagnet, I
make its cores F capable of sliding, with springs behind them, allowing them to
yield to the blow, thus providing against damage. The casing A is furnished with
a small spring plunger E which keeps the pawl B in line with C except when it is.
attracted with sufficient force to overcome the spring acting on E. The plunger E
may be arranged to make a contact when it is pushed by B, thus operating an
electric signal shewing that the lever L is unlocked. When the lever L has to be
locked and unlocked at the opposite end of its stroke I arrange the studs D and
plunger E at the other side of the casing A, and place the electro-magnet at the
other end of the quadrant Q. Also when the lever has to be locked and unlocked
at each end of its stroke, I provide an electromagnet at each end of the quadrant
and make the casing A, with a second pair of studs D¹ D¹ and a second spring
plunger E as shewn in Fig. 2.
In cases where it is desired that the spring catch rod, when released by a current
exciting the electromagnet, should remain released until the lever is moved, I
provide a catch for the pawl B as shewn in Fig. 3.
Within the casing A I pivot a loaded bell crank H which, when the pawl B has
once been attracted is caused by the load in its one arm to take the position shewn
in Fig. 3, the end of its other arm bearing against a tappet b and forming a stop
which prevents B from swinging back over the end of C.
When C is raised and the lever moved over to its other position, the momentum
of the loaded arm of H causes the bell crank to take the position indicated by the
dotted lines H', its end h then facing a slot 6¹ cut through the pawl B which is then
free to swing towards the dotted position B¹.
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 :-
:-
1. An electric lock apparatus for a railway point or signal lever, substantially as
described with reference to Figs. 1 and 2 of the accompanying drawings.
2. In combination with the apparatus above referred to, the loaded bell crank H
operating as a catch for the pawl substantially as described with reference to
Fig. 3.