An Improved Lock or Fastening for the Huts or Shelters for Enclosing the Operating Levers of Railway Points.
Year: 1894

page_text: Date of Application. 27th Oct., 1894-Accepted, 8th Dec., 1894
COMPLETE SPECIFICATION.
An Improved Lock or Fastening for the Huts or Shelters for
Enclosing the Operating Levers of Railway Points.
We, JOHN EVAN GRIFFITH, of 1 Cresswell Villas, Neath, in the County of
Glamorgan, Railway Manager, and SAMUEL TELFORD DUTTON of Marl Bank,
in the City and County of Worcester Civil 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 :--
Our invention relates to apparatus by means of which a train tablet is made to
unlock the door of a hut or shelter by its weight counterbalancing and lifting an
automatic bolt.
At outlying sidings on single line railways where the levers for working the
points are locked and unlocked by what is known as the "electric train tablet" it is
found desirable to cover in or protect the levers by a lock up shelter or hut. The
inconvenience of having to obtain and use an independent key for unlocking
the door of this hut is avoided by our invention as the tablet itself is used to unlock
the door, as well as the levers within. This is effected in the following manner :-
The tablet (which is usually a flat disc of metal) is put through an aperture of
the same size in the door and falls down a trough into a pocket or clip on a lever
or other convenient counterbalance fixed on the inside of the door. The weight of
the tablet overbalances the weight of the bolt and withdraws it. When the door
has been opened the tablet can be taken from the pocket and used for unlocking
the point levers inside the hut. The closing of the door automatically locks it by
pushing the end of the bolt over an inclined stop behind which it drops, being
weighted sufficiently to do so.
A small opening or breakable panel may be placed in the side of the hut to reach
the tablet in case the door has been accidentally or inadvertently closed and locked
before the tablet has been taken out.
In order to enable our invention to be fully understood we will proceed to describe
the same by reference to the accompanying drawing in which
Fig. 1 is a front elevation of a lock up shelter or hut shewing the bolting
apparatus in dotted lines.
Fig. 2 is a section through the door and side view of the bolt.
Fig. 3 is an enlarged view of the tablet box or pocket.
A A are the folding doors of the hut closed and locked by the bolt B.
The counterbalance preferably used is the lever C with its fulcrum pivotted at D
to the inside of one of the doors. The short arm of this lever is jointed to the
top of the bolt and the long arm to the top of a rod which carries the tablet box or
pocket E shewn on a larger scale in Fig. 3. The bolt B is heavier than the rod &
pocket when the latter is empty, and its weight overbalances the long end of the
lever and keeps the pocket up against the bottom or outlet of the trough F. The
electric train tablet shewn at G in Figs. 2 and 3 is a flat disc of metal, but the
parts of our apparatus appertaining to its use may be modified to suit the exact form
or size of the tablet used on that part of the line to unlock the levers J. J. inside
the hut. In order to open the door the tablet is put through the aperture H. and
falling down the trough F into the pocket E inside the door, is caught and held
between two springs as shewn in Fig. 3 and by its momentum and weight bears down
the long arm of the lever C raises the bolt B and unlocks the door. The vertical
arm L of the lever secures the top of the door. The cover M which is hinged and
can be thrown back is fastened down by a stud or hook on the door shewn at N.
When the door is opened and the tablet taken out of the pocket, the lever

page_text: returns to its normal position and the bolt B drops. The closing of the door forces
the bolt up the inclined stop O. behind which it drops and automatically locks
the door.
The trough F is slightly zig-zag and the bottom of the pocket E is open to
prevent or frustrate any attempt to tamper with the lock.
Having now particularly described and ascertained the nature of our said inven-
tion and in what manner the same is to be performed we declare that we
claim as our invention
1. The construction of an automatic door lock having a weighted bolt which is
counterbalanced and unlocked by the introduction of a train tablet, substantially as
described and shewn in Figs. 1. 2. and 3.
2. In combination with this lock a suitable aperture through the door and a
trough for the passage of the tablet as shewn in Figs. 1 and 2.
Dated this 26th day of October 1894.
JOHN EVAN GRIFFITH.
SAMUEL TELFORD DUTTON.