Improvements in Interlocking Apparatus for Railways.
Year: 1889

page_text: Date of Application, 9th Nov., 1889
Complete Specification Left, 9th Aug., 1890-Accepted, 20th Sept., 1890
PROVISIONAL SPECIFICATION.
Improvements in Interlocking Apparatus for Railways.
LEICESTER BRADNEY STEVENS Darlington Works Southwark Bridge Road
London S.E. Engineer, do hereby declare the nature of this invention to be as
follows:-
My invention has reference to improvements in the system of interlocking apparatus
for railways commonly called tappet locking and relates more especially
that part
known in the art as back stroke locking and the like where the tappet in addition to
other functions partakes the nature of a pawl.
The object of my invention being in cases where the tappet acts as a pawl to ensure
that it drops by other means than that of gravity only, and also prevent it being
raised unless by the proper working of the levers, it being of great importance
that the said tappet should drop when required and not fail to do so from any cause
whatsoever.
I prefer to carry my invention into effect by the use of a bevelled projection or its
equivalent on the uppermost side of the tappet this projection preferably coming
against the cover of the locking trough at the proper time when working the lover
forcing the tappet acting as a pawl down again should it fail to full by gravity.
For instance take one example of its use say a case of an advance starting and
a starting signal the movements would be as follows where the starting signal is
No. 3 and the advance No. 4, pulling over tappet 3 the tooth on its underside
passes by the side of the low level lock the bevel on the side of the tappet striking
the high level lock causing it to slide so that the low level lock is set in a line
with the tooth and also causing the V lock to come foul of the line of the wide
portion of tappet 4 this V lock being bevelled to allow tappet 4 to rise over it in
coming over, my bevelled projection on its uppermost side then forcing it down after
it has passed over, tappet 3 is now free to be replaced and in so replacing it the tooth
on its undermost side raises it past the low level lock when my projection on its
uppermost side coming in contact with the cover of the locking trough or its
equivalent forces tappet 3 down where it stands locked until tappet 4 has been
replaced so taking off the lock set by tappet 3 and setting the lock normal
again.
Dated this 9th day of November 1889.
COMPLETE SPECIFICATION.
Improvements in Interlocking Apparatus for Railways.
1 LEICESTER BRADNEY STEVENS of Darlington Works, Southwark Bridge Road in
the County of Surrey, 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 :—
My invention has reference to improvements in the system of interlocking apparatus
for railways commonly called tappet locking, and relates more especially to that part
known in the art as back stroke locking and the like where the tappet in addition to
other functions partakes of the nature of a pawl, the object of my invention being in
cases where the tappet acts as a pawl to insure that it shall drop by other means than
that of gravity only, and also to prevent it being raised unless by the proper working
of the levers, it being of great importance that the said tappet should drop when
required and not fail to do so from any cause whatsoever.

page_text: I prefer to carry my invention into effect by the use of a bevelled projection or its
equivalent on the uppermost side of the tappet, this projection preferably coming
against the cover of the locking trough at the proper time when working the lever,
forcing the tappet acting as a pawl down again should it fail to fall by gravity.
In the accompanying sheet of drawings :-
:-
Fig. 1 is a perspective view of the lower part of a pair of signal levers, tappets
and locks for a "starting" and "advance starting" signal constructed according to
this invention, and
Fig. 2 represents a vertical transverse section through the locking trough in which
the locks and tappets work.
To the starting signal lever a is hinged the tappet 3 narrowed at 6 and having a
bevel c for engaging with the bevel d on the high lock block e. On the underside of
the tappet is a pawl tooth which when the locking bolt g is in the position shown is
free to pass between the high lock block e and the low lock block h. When however
the lever a is pulled over so that the bevel c engages with the high lock block e the
locking bolt g is slid in the locking trough bringing the low locking block into the
path of the pawlf so that when the lever a is returned to its normal position the pawl f
passes over the block h, the bevelled projection or cam i engaging with the cover k of
the locking trough t, depressing the tappet 3 and pawl, and securely locking the
signal lever a.
To the advance starting lever is hinged the tappet 4 narrowed at m and provided
on its underside with a bevel n for engaging with a corresponding bevel o on the
locking bolt g. A recess or notch with bevel p is also formed in the tappet 4 to fit
the end of the locking bolt y so that when the lever is pulled over the bevels no
cause it to rise and pass over the block e the projection 9 engaging with the locking
trough cover k causing the notch p to fall over the end of the bolt
g.
The operation of a pair of "starting" and "advance starting" signals as shown is
as follows, where the starting signal is No. 3 and the advance No. 4. Pulling over
tappet 3 the tooth on its underside passes by the side of the low level lock h, the
bevel c on the side of the tappet striking the high level lock e and causing it to slide
so that the low level lock his set in a line with the tooth fand also causing the
V lock to come foul of the line of the wide portion of tappet 4, this V lock being
bevelled at o to allow tappet 4 to rise over it in coming over the bevelled pro-
jection 9 on its uppermost side then forcing it down after it has passed over. 1 .ppet 3
is now free to be replaced and in so replacing it the tooth fon its undermost side
raises it past the low level lock when the projection on its uppermost side engaging
with the cover of the locking trough or its equivalent forces tappet 3 down, where
it stands locked until tappet 4 has been replaced, the bevel p engaging with
bolt g and so taking off the lock set by tappet 3 and setting the lock normal
again.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed, I declare that what I
claim is :-
:-
1° In interlocking apparatus for railways, constructing the tappets with projections
for engaging with the locking trough cover or its equivalent so as to ensure the
falling of the tappets independently of the action of gravity and to prevent them
being raised except by the proper working of the levers substantially as described.
20 The arrangement and construction of interlocking apparatus for railways sub-
stantially as described with reference to the drawings.