Improvements in Apparatus for Automatically Closing Bulkhead Watertight Doors.
Year: 1897

page_text: Date of Application, 23rd Jan,
1897
Complete Specification Left, 23rd Oct., 1897-Accepted, 23rd Feb.,
1898
PROVISIONAL SPECIFICATION.
Improvements in Apparatus for Automatically Closing Bulkhead
Watertight Doors.
WILLIAM CRAWFORD, 46, Muse Lane, of the County of the City of Glasgow,
Tinsmith, North Britain, and ALEXANDER ROBINSON CRAWFORD, of the same place,
Tinsmith, do hereby declare the nature of this invention to be as follows:-
Our said invention has for its object improvements in automatically closing water-
tight doors on ships' bulkheads.
Our improved apparatus consists of an air chamber placed in the lower parts of a
ship, with pipe leading from the top of the same to a metal casing with a leather or
other diaphragın mounted with suitable metal plate and guiding pins with sufficient
shape, to actuate on each door releasing lever.
To prevent a heavy door when released moving too quick we bring the door to a
suitable balance by weights, air cylinders, springs or other known mechanism.
Aforesaid air chamber if of sufficient capacity can actuate any number of doors
irrespective of position and of course simultaneously.
The air chamber is connected by a small pipe with aforesaid metal casing enclosing
the flexible diaphragm and when air is compressed by any inflow of water the air
moves diaphragm and lever; releases door and brings about the closing of same.
1807
WILLIAM CRAWFORD.
A. R. CRAWFORD.
Improvements in Apparatus for Automatically Closing Bulkhead
Watertight Doors.
We, WILLIAM CRAWFORD, Tinsmith, and ALEXANDER ROBINSON CRAWFORD, Tinsmith,
both of 46, Muse Lane, in the County of the City of Glasgow, 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 said invention has for its object improvements in automatically closing water-
tight doors on ships bulkheads.
As illustrated by the accompanying drawings, Figure 1 of which is an elevation
partly in section, Figure 2 a plan and Figure 3 an end view, the improved apparatus
consists of an air chamber A placed in the lower part of a ship and having a pipe B of
small bore led from its upper end to a metal casing C within which is secured a
leather or other diaphragm provided with suitable plates and guiding pins D, D¹,
one D¹ of which, when the air pressure is sufficient to actuate the diaphragm, acts

page_text: upon a releasing lever E so as to withdraw a pin F which normally holds a half nut G
against the action of a spring G¹ in gear with the usual threaded spindle H carried
on the door I, and by so releasing the nut permits the door to fall by its own weight;
or the releasing of the door may be effected by the air pressure actuating any other
mechanical device, the pin D¹ of the diaphragm in either case acting on the door
releasing lever. The air chamber A may be of sufficient capacity to actuate any
number of doors simultaneously and irrespective of position, a metal casing having a
diaphragm being provided for each door.
To prevent a heavy door when released from falling too quickly suitable counter-
balance weights, air cylinders, spring or other mechanism may be applied.
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 what we
claim is :-
The improved apparatus for automatically closing watertight doors for ships bulk-
heads comprising an air chamber wherein air is subjected to pressure by water rising
in the bilges, said chamber being connected to a diaphragm and lever actuated by
the air pressure to effect the release of the door substantially as described.
Dated finish day of October 1037
WALLACE FAIRWEATHER,
Of the Firm of Cruikshank & Fairweather,
Chartered Patent Agents,
62, Saint Vincent Street, Glasgow, Agent for the Applicants.