An Improved Automatic Watertight Ventilation Valve.
Year: 1899

page_text: Date of Application, 29th Mar., 1899-Accepted, 2nd June, 1899
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COMPLETE SPECIFICATION.
An Improved Automatic Watertight Ventilation Valve.
I, JAMES GRIGG, Works Manager, The Fairfield Shipbuilding and Engineer-
ing Co., Limited, Goran, 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:-
This invention relates to an improved watertight valve, for use with the ventila-
tion system in ships, which can be automatically closed from some convenient
point of the vessel should a collision or other accident occur and it is desired to
cut off communication between the various compartments by the ventilation of
pipes or trunks; also, should one compartment become filled with water by any
means, to enable the water when it reaches the level of the valve to automatically
close the said valve and prevent it gaining access to the compartment beyond, and
has for its object to so construct the valve that it is self contained; completed,
adjusted and tested before being sent to the ship and when attached to the bulk-
head or casing not affected by any warping which may take place so that the valve
is always maintained in efficient working order.
But in order that my said invention may be more readily understood and easily
carried into effect I have hereunto appended an explanatory sheet of drawings in
which
Fig. 1 is a front elevation, partly in section
Fig. 2 a cross section, and
Fig. 3 a horizontal section through the centre of the inlet and outlet, of my
improved valve, the valve being in its closed position.
Fig. 4 is a horizontal section at the fulcrum of the counterbalanced lever, the
valve being in a half open position.
Referring to the said drawings, the valve consists of a casing formed in two
halves A A bolted together and provided with two circular flanges B B' for attach-
ing to the bulkhead or pipes, the inside face of the back casing A¹ forming the
valve seating. The front casing is cast with a small chamber C in its lower part,
forming the float chamber; and can be made to take either a circular shaped
trunk or pipe, as shewn, or one of a rectangular section.
The valve consists of a rectangular shaped flat plate or shutter D webbed for
strength, and provided with tongues d on its edges which slide in grooves d¹
formed in the back casing A¹. There is a tapered strip at each side of the shutter,
indicated in Fig. 2 by the dotted line e, which, acting against corresponding
'keeps" E screwed to the back casing A', serve to wedge the shutter home when
it is raised to shut. The operating lever consists of an inside part F fitted with
a trigger f on its end and with a roller attached by a stud f, or otherwise, which
roller works in a recess f³ on the face of the valve plate or shutter. The fulcrum G
of this lever is cast in one piece with the inside part, passes through a boss g,
raised on the casing A, and is fitted with an outside lever F which is pinned or
otherwise secured to it and provided with an adjustable counterbalance weight F
which serves to close the valve when the trigger f is released.

page_text: A tripper H is fitted to the inside of the front casing A and catches over the
end of the trigger f, the end of the said tripper being fitted with a small roller h.
The tripper is thrown back by the raising of a float J, working in the float cham-
ber C, before referred to, and which is provided with a roller at the top thereof,
which rolls within the end of the tripper, permitting the float to rise without
jamming. Water to raise the float and so release the valve is led by a copper or
other pipe K, from some convenient point, to the valve casing where the fulcrum
pin passes through. A passage or port L is arranged partly through the fulcrum
pin forming a continuation of the pipe K when the valve is open and from this
passage the water is led by a short pipe to directly over the float chamber. 1
The water thus makes its way to the float chamber and serves to raise the
float J, which, acting through the tripper, releases the trigger on the lever.
The shutter being now free to move is forced upward by the action of the
counterweight and wedges itself home against its seating.
By the turning of the fulcrum pin the passage of water is immediately cut off, 1
and no more can enter the float chamber than is necessary to release the valve.
A small drain plug is fitted in the bottom of the float chamber to drain off the
water. To set the valve in the open position the water is drained from the float
chamber thus permitting the float to sink to the bottom. The valve is forced
open by raising the weight F on the outside so that the trigger f, which is
formed with a sloping underside along which rolls the small wheel or roller h
in the end of the tripper, causes the tripper to hinge back on its fulcrum pin and
catch on the top of the trigger when the roller passes the end of the trigger.
The valve will also be closed by water entering the ventilation pipe or trunk
from above through the vent pipe or by water rising above the level of the access:
door M of the float chamber when such door is not made watertight.
Having now particularly described and ascertained the nature of my said
invention, and in what manner the same is to be performed, I declare that what
I claim is:-
1. The general arrangement, construction and combination of parts constituting
the automatic watertight ventilation valve for ships, substantially as hereinbefore
described and shewn in the accompanying drawings.
2. In automatic watertight ventilation valves, the rectangular shutter D, pro-
vided with tongues / sliding in grooves formed in the back casing A¹ and having
a tapered strip at each side arranged to act against the ". keeps" E, all arranged
substantially as and for the purpose hereinbefore described and shewn in the
accompanying drawings.
3. In automatic watertight ventilation valves, the means whereby water is
supplied to the float chamber to close the valve, and cut off when so closed, con-
sisting of a port or passage formed in the fulcrum pin of the counterbalanced lever
which engages with the shutter, arranged substantially in the manner as heroin-
before described and shewn in the accompanying drawings.
JOHNSONS,
Applicant's Agents, 115, St. Vincent Street, Glasgow.