Improvements in Apparatus for Automatically Closing Bulkhead Watertight Doors.
Year: 1898

page_text: Date of Application, 4th Mar., 1898-Accepted, 30th Apr., 1898
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 per-
formed, to be particularly described and ascertained in and by the following
statement:
Our invention relates to watertight doors for ships' bulkheads of the kind
described in the Specification of Letters Patent granted to us No. 1802 of 1897, and
wherein air pressure within an air chamber produced by accumulation of water in
the ships' bilges or other part of the ship is utilized to effect the release of the
devices employed to retain the doors normally in the open position, so that the
doors are closed automatically in case of accident to the ship.
The invention has for its objects to provide simple and improved means for
retaining the doors in the open position whilst permitting of their ready automatic
release, also to provide in conjunction with the automatic releasing devices, means
for opening and closing the doors from the deck or other part of the ship, and
further to provide means whereby the speed of the door in the early part of its
descent may be retarded and accelerated in the final closing.
In the accompanying drawings, Figure 1 is an elevation, Figure 2 a horizontal
section on the linear, of Fig. 1, and Figure 3 a transverse vertical section on
the line yy, of Fig. 1, illustrating a watertight door as operated by a modifica-
tion of the apparatus constituting our invention. Figures 4 and 5 are views at
right angles to each other of a modified form of part of the apparatus, and Figures 6
and 7 are respectively an elevation and plan showing a further modification.
As represented in Figures 1, 2 and 3 of these drawings the apparatus comprises
a chamber A placed in the lower part of the ship and within which air is confined
and is subjected to compression, in the event of accident to the ship, by the rising
of the water in the bilges as is indicated at Figure 1. From the upper end of this
chamber A a pipe B of small bore is led to a metal casing C within which is
secured a leather or other diaphragm provided with suitable plates and guiding
pins D, D¹, one 1)1 of which, when the air pressure is sufficient to actuate the
diaphragm, acts upon a releasing lever E. According to the present invention
this lever E when actuated by the diaphragm acts on and withdraws a clutch F
keyed upon a horizontal shaft G and engaging normally with a bevel wheel H
loosely centred on said shaft. On the shaft G a pair of spur wheels G¹ are keyed
which engage with racks I on the bulkhead door J. The bevel wheel H is geared
to a bevel wheel K on a vertical shaft L which extends to the deck and can be
operated therefrom to raise the bulkhead door, a hand wheel M being also provided
at the lower end of the shaft L and at the side of the door so that the shaft can
be there operated to raise the door. A cylinder N is provided on the door between
the racks I in which is a loosely fitting piston O, the rod P of the piston being pre-
ferably hollow and secured to the bulkhead at its upper end. This cylinder is

page_text: filled with glycerine or other liquid and is of larger diameter at its top end or has
an enlargement or bye-pass formed on it so as to permit of the easier passage of
the glycerine to the other side of the piston at that end of the cylinder, and thus
allow the door to fall sharply into its closed position by the acceleration due to
gravity. The door is raised by rotating the vertical shaft L either from the deck
or from below as before described, the clutch being, during this operation, thrown
into gear with the bevel wheel H, by a spring or weight. The door, after being
raised, is prevented from falling by means of the ratchet wheel Q and pawl R on
the vertical shaft L. When it is desired to close the bulkhead doors without
employing the air pressure in the air vessel, or when the pressure in the air vessel
is nil the clutch F can be released from the bevel wheel H from the deck by means
of a rope S as shown, or by other means. 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.
Instead of employing a clutch to engage the bevel wheel H a ratchet wheel T
may be secured upon the horizontal shaft G, as shown at Figures 4 and 5, the
bevel H being in this case keyed on the shaft G. A beam lever is provided, one
end of which is acted upon by the pin D' of the diaphragm the other end acting
as a pawl to prevent the rotation of the ratchet wheel T and thus hold the door
in its raised position. On the withdrawal of the pawl the door is free to fall by
its own weight.
In the modification shown at Figures 6 and 7 a worm wheel U is fitted loose
on the horizontal shaft G and engages with a worm U¹ on the vertical shaft L. On
the shaft G is keyed a disc V in close proximity to the worm wheel U and the latter
is prevented from turning on its shaft G by means of pins or prongs f on a
sliding clutch F1 fitted loose on the shaft G, the said prongs f being, by sliding
movement imparted to the clutch, protruded through orifices in the fixed disc V
and into like orifices in the worm wheel U. The sliding clutch F is actuated by
the releasing lever E from the diaphragm pin 11, in order to withdraw the
prongs from engagement with the loose worm wheel U and fixed disc V and thus
allow the door to fall by its own weight. The raising of the door from the deck
or elsewhere is effected by turning the shaft L so that the worm U₁ acts on the
worm wheel U whilst the latter is held fast on the horizontal shaft G by means of
the clutch F¹ and the fixed disc V.
The door may in a further modification be suspended in its raised position by
fluid or air pressure, the pressure being supplied by pumps or otherwise, and
cocks being provided which are operated by the air diaphragm to permit the outflow
of the pressure water or air and allow the bulkhead door to fall by its own weight,
or in the case of horizontally moving doors these may be closed by fluid or air
pressure or by weights so arranged as to be freed in order to close the door by the
operation of the levers or devices actuated by the movement of the diaphragm due
to increased air pressure in the chamber A.
In a further modification not shown by the drawings, the door is formed with a
series of teeth or notches in its side or edge with one of which the catch lever
operated from the diaphragm normally engages; and upon the withdrawal of
the catch lever the door is free to fall whilst in again raising the door the catch
lever by engaging with the teeth or notches prevents its descent.
A piston closely fitting a cylinder may be used in substitution for the diaphragm
described, the piston being moved within the cylinder by the air pressure and
being formed with a short piston rod projecting through one end of the cylinder
to operate the catch lever.
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 :-
1 The combination of parts constituting the improved annaratus for automati

page_text: cally releasing and gradually closing watertight doors and for raising or lowering
them from the deck or other part of the ship, substantially as described under
several modifications with reference to the accompanying drawings.
2. The combination with a watertight door of a rack or racks secured thereon
and gearing with pinions on a horizontal shaft which normally holds up the door
said shaft being fitted with a sliding clutch operated to release the shaft and door
by means of a lever acted on by a diaphragm actuated by rise of pressure of air
confined in an air chamber substantially as described.
3. In apparatus for automatically closing ships' bulkhead doors, the arrange-
ment in combination with a diaphragm and releasing lever operated by compression
of air in an air chamber of a horizontal shaft provided with toothed wheels
engaging racks on the bulkhead door, and a vertical shaft geared thereto and
extending to the deck, said vertical shaft being adapted for operating the door
from the deck whilst serving to prevent the falling of the door substantially as
described.
4. In combination with a ships' bulkhead door the provision of a cylinder filled
with oil, glycerine or other liquid having a loosely fitting piston, the cylinder being
formed or fitted with a bye-pass so that the liquid serves to retard the speed of the
falling door during the early part of its movement whilst allowing the door to fall
sharply to its closed position substantially as described.
5. The combination with a watertight door of a cylinder containing oil, glycerine
or other liquid and formed with a bye-pass and having a loosely fitting piston, a
rack on said door geared to a horizontal shaft which is held to normally retain
the door in its open position and is freed by the action of a releasing lever on a
clutch, ratchet or like device the said releasing lever being operated automatically
by increase of air pressure within an air chamber substantially as described.
Dated this 3rd day of March 1898