AN IMPROVED LOCK, SELF-ACTING AND OTHERWISE, FOR RAILWAY AND OTHER Carriage Doors
Year: 1871

page_text: PROVISIONAL SPECIFICATION left by John King at the Office of
the Commissioners of Patents, with his Petition, on the 22nd July
1871.
I, JOHN KING, of 9, Union Court, Old Broad Street, City of London,
Wholesale Ironmonger and Hardware Manufacturer, do hereby declare
the nature of the said Invention for "AN IMPROVED LOCK, SELF-ACTING AND
OTHERWISE, FOR RAILWAY AND OTHER Carriage Doors,” to be as follows :-
:-
I fit a plate of metal of convenient length and thickness and as nearly
as possible to the same width as the carriage door pillars. On the
middle of the width of this plate I fix a tube parallel with and extending
from one end of the plate towards the middle of its length. The
tube end is the top of the lock when it is in its position on the carriage
door.
I do not confine myself as to the kind of metal I shall use. If
made of cast metal the said plate and tube will form one casting. In
the said tube I place a coil or other kind of spring. I secure the top
end of the tube with a screw for convenience of changing the spring.
I make the tumbler, or the part that goes into the door staple, with
pivots, one at the top and another at the bottom of the tumbler. I fit
one pivot into the said tube for the spring to act upon it and the other

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into a hole in a stud, which stud I rivet or otherwise fasten to the
bottom end of the said plate in a line with the tube containing the
spring at the top end of the plate. I make a slot down the middle of
the tumbler, and on one side of the slot I make two or more inclined
teeth, and on the spindle of the door handle I make two or more
inclined teeth to fit into those in the slot. I fit the tumbler into its
place on the plate, so that there is a space between the plate and the
tumbler for the latter to move on its pivots.
I fix to the plate in the space mentioned, and near to the edge of
the plate, a piece of metal or steel, which I shall call a step, so that
when the tumbler is down to its extreme position it cannot move on its
pivots, but when the handle is turned from its horizontal to its per-
pendicular position the tumbler is raised just clear of the top of the said
step, and slips on to the latter by the pressure of the spring on the
inclined teeth. The handle is thus kept in its perpendicular position,
showing the guard or other person or persons at a distance that the
carriage door is not fastened. I make the staple open at the top and
higher on the side next to the door pillar, so that when the door is
pushed from the outside or pulled from the inside of the carriage the
projecting part of the tumbler strikes against the higher part of the
staple, slips off the step, and is forced by the spring into the staple,
bringing the handle again into its horizontal position, and the door is
secure.
I screw the lock and the staple to the outside of the carriage door
pillars.
I make the said lock otherwise than self-acting by fitting the slot in
the tumbler, so that a camb or projection which I fit to or make in one
with the spindle of the carriage door handle shall raise the tumbler out
of the staple or lower it therein according to the way the handle is
turned by the hand, the spring acting on the pivot of the tumbler as
before described.
I make the said staple as already described, or with one side of it
conveniently inclined to meet the tumbler of the lock, should the tumbler
be left down when the carriage door is open.