An Improvement in Point Locks for Railways.
Year: 1893

page_text: Date of Application, 6th Mar., 1893
Complete Specification Left, 2nd Aug., 1893-Accepted, 2nd Sept.. 1893
PROVISIONAL SPECIFICATION.
An Improvement in Point Locks for Railways.
I, CHARLES HODGSON, of Canterbury Road, Kilburn, in the County of
Middlesex, Engineer, do hereby declare the nature of this invention to be as
follows:-
In many cases, it is necessary or desirable to lock some of the points of railways
so that they cannot be moved except at the will of an official who possesses the
key, which may be attached to or form part of the safety staff often carried by
trains on single lines.
Such locks as are at present employed are usually applied to the levers or rods
by which the points are moved, but, owing to looseness of joints, stretching of
rods and other causes, the tongues or switch rails of the points which are locked
are not always kept close home to the stock rails, and there is consequently risk of
accident to trains passing points in this condition.
According to my present invention, I bolt to the stock rail near the end of a
switch rail a lock having a strong sliding bolt which can be pushed back by
hand clear of the switch rail, leaving that rail free to be moved, or which can
be pushed forward by hand so as to overlap the end of the switch rail when it
is home against the stock rail, in which position of the bolt it is locked by a small
key introduced into the lock and turning a spring tumbler therein.
The bolt of the lock is widened at its end so that, when the switch rail is moved
away from the stock rail, the end of the switch rail forms a stop, preventing the
bolt of the lock from being moved forwards. Or the widening of the end of the
bolt may be such that when the switch rail is moved away from the stock rail,
the widened part can be interposed between the stock rail and the end of the
switch rail and locked in that position, thus holding the switch rail firmly when it
is away from the stock rail, when this is necessary. As the bolt which is required
to be strong, is not moved, but only locked by the key, this key may be com-
paratively small and light.
Dated this 6th day of March 1893.
ABEL & IMRAY,
Agents for the Applicant.
COMPLETE SPECIFICATION.
An Improvement in Point Locks for Railways.
1, CHARLES HODGSON, of Canterbury Road, Kilburn, in the County of
Middlesex, 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 many cases it is necessary or desirable to lock some of the points of railways
so that they cannot be moved except at the will of an official who possesses the
key, which may be attached to or form part of the safety staff often carried by
trains on single lines.
Such locks as are at present employed are usually applied to the levers or rods
by which the points are moved, but owing to looseness of joints stretching of rods
and other causes the tongues or switch rails of the points which are locked are not
always kept close home to the stock rails, and there is consequently risk of accident
to trains passing points in this condition.
According to my present invention I bolt to the stock rail near the end of a
Price 8d1

page_text: switch rail a lock having a strong sliding bolt which can be pushed back by hand
clear of the switch rail leaving that rail free to be moved, or which can be pushed
forward by hand so as to overlap the end of the switch rail when it is home
against the stock rail, in which position of the bolt it is locked by a small key
introduced into the lock and turning a spring tumbler therein..
Fig. 1 of the accompanying drawings is a side view of a point lock according to
my invention with the cover of the lock removed.
Fig. 2 is a transverse section Fig. 3 is a sectional plan and Fig. 4 is a front view
of the cover of the lock.
S is the stock rail to which near the end P of the moveable switch rail, is
bolted the lock consisting of a casing L with cover C. Within the casing is
pivotted a tumbler T of cylindrical form with its sides flattened, the front part
of the tumbler having two notches the one or the other of which is engaged
by a spring catch D according as the tumbler T is in the position shewn or
turned one quarter of a revolution round until its flat side meets a stop t, the
catch D holding it with certain firmness in either of these positions. A strong
bolt B is fitted to slide through the lock, this bolt having through it a slotted
hole H with rounded hollows to receive the cylindrical parts of the
tumbler T. K is a small light key, which may form part of or may be attached
to the safety staff. In the position shewn, the end of the bolt B overlaps the end
of the switch rail P holding that rail close against the stock rail so that it cannot
be moved. But when the official who has the key inserts it into the lock and
turns the tumbler T one quarter round so that its flat sides are parallel to the
slot H, he can then by hand push back the bolt B so that its end is off the
switch rail P which can then be moved away from the stock rail. The bolt B
has its end widened so that when the switch rail P is moved away from the
stock rail to the position P1, the widened end of the bolt at B₁ is stopped by the
end of the switch rail and the bolt cannot then be pushed forwards, and con-
sequently the key, which has been turned half round to release the bolt, cannot be
withdrawn until the bolt is again pushed forwards and locked. The end. of the
bolt B may, however if desired, be made of such width that when the switch
rail P is moved to P₁ the bolt end can be interposed between P1 and the stock rail,
and the bolt can be locked holding the switch rail in the open position. As the
bolt B, which is necessarily strong and heavy, is not moved by the key but by
hand, the key required is comparatively small, light and portable.
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 :-
A point lock, fixed to the stock rail close to the end of the switch rail and pro-
vided with a sliding bolt that can be moved by hand so that its end overlaps the
end of the switch rail and can be locked in that position by a light key, substantially
as and for the purpose set forth.
Dated this 2nd day of August 1893.
ABEL & IMRAY,
Agents for the Applicant.