Improvements in Locks for the Doors of Railway and other Carriages.
Year: 1887

page_text: Date of Application, 8th Sept., 1887
Complete Left, 8th June, 1888
Complete Accepted, 13th July, 1888
Improvements in Locks for the Doors of Railway and other
Carriages.
We, WILLIAM HOLMES NISBET, Mavisbank Partick, Lanarkshire, Engineer, and
WILLIAM WRIGHT VIRTUE of 505 Springburn Road, Glasgow Engineer, do hereby
declare the nature of this invention to be as follows:
Our invention relates to improvements in locks for the doors of railway and other
carriages the improved lock being adapted to act automatically upon the closing of
the door the bolt being fully shot either by or without the aid of the ordinary door
handle.
The improved lock which is constructed with a casing to fit in a mortice in the door
in the usual way, is formed with a sliding spring bolt whose outer end is bevelled and
projects beyond the mortice plate so as to be struck and shot back by the striking
plate on the door frame when the door is closed; and on the inner end of the bolt is
formed a tail piece having a bearing upon a tumbler secured on the spindle on which
the door handle is fixed a shoulder being formed on the tumbler to bear on the end of
the tail piece so as to prevent the bolt being fully shot or the handle being turned by
hand excepting in the direction for unlocking the door. By preference a single spring
is employed to operate both the bolt and the tumbler the said spring being made either
in the form of a blade spring suitably bent to bear directly upon the end of the bolt
and upon a shoulder on the tumbler, or in the form of a helical spring connected to
levers bearing respectively on the bolt and tumbler.
Upon the closing of the carriage door the bolt being thrown back by the striking
plate the shoulder on the tumbler is freed from the tail piece and the tumbler is by
the action of the spring thrown over clear of it so that the bolt may be fully shot to
lock the door the handle at the same time assuming the horizontal or locked position.

page_text: On turning the handle to unlock and open the door the bolt is first fully shot back by
the tumbler and on the end of the bolt clearing the striking plate the bolt is thrown
to the intermediate position in which it is held by the tumbler with the bevelled end
projecting. In cases in which it is considersd desirable that the door handle should be
turned by hand to the position in which the bolt is fully shot the locking shoulder upon
the tumbler is omitted and a longer bearing provided upon the tail piece of the bolt so
that the tumbler may retain the bolt normally in the half shot position whilst being
capable of being turned by the bandle to allow the bolt to be fully shot.
Dated this Seventh day of September 1887.

page_text: We, WILLIAM HOLMES NISBET, Mavisbank Partick, Lanarkshire, Engineer, and
WILLIAM WRIGHT VIRTUE of 12 Queen's Crescent, New Cathcart, Renfrewshire,
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 improvements in locks for the doors of railway and other
carriages the improved lock being adapted to act automatically upon the closing of
the door, the bolt being fully shot either by or without the aid of the ordinary door
handle.
As represented under several modifications at figures 1, 2 and 3 of the accom-
panying drawings the improved lock which is constructed with a casing A to fit in a
mortice in the door in the usual way, is formed with a sliding spring bolt B whose
outer end b¹ is beveled and projects beyond the mortice plate C so as to be struck and
shot back by the striking plate on the door frame when the door is closed; and on
the inner end of the bolt B is formed a tail piece 6 having a bearing upon a tumbler D
secured on the spindle E on which the door handle is fixed, a shoulder d being formed
on the tumbler to bear on the end of the tail piece b so as to prevent the bolt being
fully shot or the handle being turned by hand excepting in the direction for unlocking
the door. By preference a single spring F is employed to operate both the bolt B and
the tumbler D the said spring being made either in the form of a blade spring suitably
bent as shown for example at figures 2 and 3 to bear upon the end of the bolt B and
upon a shoulder d' on the tumbler D, or in the form of a helical spring connected to
levers G and H bearing respectively on the bolt and tumbler as shown at figure 1.
Upon the closing of the carriage door the bolt B being thrown back by the striking
plate the shoulder d on the tumbler is freed from the tail piece and the tumbler D
by the action of the spring F thrown over clear of it so that the bolt may be fully
shot, (as indicated by the dotted lines in figure 1) to lock the door, the handle at the
same time assuming the horizontal or locked position. On turning the handle to
unlock and open the door the bolt B is first fully shot back by the tumbler D and on
the end 6' of the bolt B clearing the striking plate in the door frame the bolt is thrown
to the intermediate position in which it is held by the tumbler with the beveled end b¹
projecting. In cases in which it is considered desirable that the door handle should
be turned by hand to the position in which the bolt is fully shot in locking the door
the locking shoulder (d) upon the tumbler D is omitted or is so inclined as to permit
of the tumbler being turned a longer bearing being provided upon the tail piece of
the bolt B so that the tumbler may retain the bolt normally in the half shot position
whilst being capable of being turned by the handle to allow the bolt to be fully shot.
This construction of the improved lock is represented under different modifications at
is

page_text: figures 1a, 2a and 3a of the drawings. In these last forms of locks, which are not
fully automatic in action, the arrangement whereby the spring F acts on the tumbler D
is omitted.
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed we declare that what we
claim is :-
1. The combination of parts constituting the improved carriage door lock herein-
before described under different modifications with reference to figures 12 and 3 of
the annexed drawings.
2. The combination of parts constituting the improved carriage door lock herein-
before described under different modifications with reference to figures 1a, 2a, and 3 a
of the annexed drawings.
3. The combination in a lock for carriage doors of a locking bolt provided with tail
piece a tumbler connected to the usual handle and engaging the tail piece and a spring
arranged to act directly or through a lever on the bolt substantially as described.
4. The combination in a lock for carriage doors of a locking bolt provided with tail
piece a tumbler connected to the usual handle and engaging the tail piece and a spring
or springs acting directly or through levers on the bolt and tumbler, the parts being
so arranged and operating that the bolt is automatically shot on the closing of the door
substantially as described.
Dated this Seventh day of June 1888
CRUIKSHANK & FAIRWEATHER,
62, Saint Vincent Street, Glasgow,
Agents.