Year: 1898

page_text: JOHN SANDERS STEVENS, CHARLES GEORGE MAJOR, and EDWIN CHARLES STEVENS,
Engineers, of Janus Works, Queen's Road, Battersea, in the County of London, do
hereby declare the nature of this invention to be as follows:-
In working bydro pneumatic accumulators, which are vessels partly filled with
water & the remaining part with compressed air, the latter being employed to expel
the former under pressure for the purpose of actuating hydraulic machinery, a
difficulty frequently arises in the following manner.
The receiver may have been surcharged with air; the replenishing pumps may
have been temporarily stopped; or the work performed by the driven machinery may
have been abnormally lightened. Under either of these conditions, or a combination
of any of them all the water might be expelled from the accumulator, & air following
would find its way to the driven machinery & cause dangerous results.
Our invention has for its object the prevention of such improper exhaustion of
water; & for this purpose we fit the mouth of the outlet pipe from the receiver with
a perforated rose piece, loosely covered by a floating bell suitably balanced. The bell
has attached to it a displacement float of stone or other suitable material, & their
combined weight is nearly but not entirely balanced by weights placed high up
within the receiver, so as to be always in the air space & never immersed in water.
The action is as follows; so long as the normal amount of water remains in the
accumulator, the bell is floated & the opening to the outlet pipe is left uncovered.
But should the water fall below a predetermined level the bell will descend with it &
gradually cut off the flow through the rose. If the feed pumps are working the bell
acts as a perfect governor restricting the passage to the pipe till the escape of water
is made equal to the quantity supplied by the pumps, & the water level will remain
constant at the height proper to that position of the floating bell.
Should the pump increase its delivery the water level rises till the bell opens a
correspondingly increased aperture for escape-& vice versa for a decreased supply
from pumps.
Should the pumps be stopped entirely, the bell will completely close the aperture
while it is still safely drowned, before any air is allowed to pass.
of escape,
A by pass cock is sometimes fitted to put the bell into equilibrium again to enable
it to rise. In other cases where a perfect closure is not requisite the bell is permitted
a slight leakage which automatically keeps it in equilibrium.
The floating valve may be placed in an enlargement of the outlet pipe instead of
in the accumulator.
Other forms of floating valve may be employed, or valves actuated by floats
effecting the same purpose, without departing from the principle of our invention.
Dated this Eighth day of October 1898.
JOHN SANDERS STEVENS.
CHARLES GEORGE MAJOR.
EDWIN CHARLES STEVENS.

page_text: Improvements in Hydro-pneumatic Accumulators.
JOHN SANDERS STEVENS, CHARLES GEORGE MAJOR, and EDWIN CHARLES STEVENS,
Engineers, of Janus Works, Queen's Road, Battersea, in the County of London, 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 :-
In working hydro-pneumatic accumulators, which are vessels partly filled with
water & the remaining part with compressed air, the latter being employed to expel
the former under pressure for the purpose of actuating hydraulic machinery, a
difficulty frequently arises in the following manner.
The receiver may have been surcharged with air; the replenishing pumps may
have been temporarily stopped; or the work performed by the driven machinery may
have been abnormally lightened. Under either of these conditions or a combination
of any of them all the water might be expelled from the accumulator, & air following
would find its way to the driven machinery & cause dangerous results.
Our invention has for its object the prevention of such improper exhaustion of water,
& for this purpose we fit the mouth of the outlet pipe A Fig. 1 from
the receiver B with a perforated rose piece C loosely covered by a floating
bell D suitably balanced. The bell has attached to it a displacement float E of stone
or other suitable material & their combined weight is nearly but not entirely balanced
by weights F placed high up within the receiver so as to be always in the air space &
never immersed in water.
The action is as follows; so long as the normal amount of water remains in the
accumulator B the bell D is floated & the opening to the outlet pipe A is left
uncovered. But should the water fall below a predetermined level the bell will
descend with it & gradually cut off the flow through the rose.
If the feed pumps are
working the bell acts as a perfect governor restricting the passage to the pipe till the
escape of water is made equal to the quantity supplied by the pumps, & the water
level will remain constant at the height proper to that position of the floating bell.
Should the pump increase its delivery the water level rises till the bell opens a
correspondingly increased aperture for escape―& vice versa for a decreased supply
from pumps.
Should the pumps be stopped entirely, the bell will completely close the aperture
of escape, while the latter is still safely drowned, & before any air is allowed to pass.
A by pass cock G is sometimes fitted to put the bell D into equilibrium again to
enable it to rise. In other cases where a perfect closure is not requisite the bell is
permitted a slight leakage which automatically keeps it in equilibrium, & we prefer
this arrangement.
The floating valve D may be placed in an enlargement of the outlet pipe instead of
in the accumulator.
Other forms of floating valve may be employed, or valves actuated by floats effecting
the same purpose, without departing from the principle of our invention.
.
For instance the balance weights F may be carried as in Fig. 2 by a chain & wheel
instead of on levers.
Or the bell valve D may be replaced as in Fig. 3 by an ordinary double beat
equilibrium valve.
Or instead of a bell valve outside a rose, a solid piston D as in Fig. 4 may be used
passing freely up & down inside a perforated rose, & seating itself on the bottom face
when closed.

page_text: Having now particularly described and ascertained the nature of our said
invention, and in what manner the same is to be performed, we declare that
what we claim is :-
1. In combination with a hydro-pneumatic accumulator, a governing valve as
described for preventing the complete exhaustion of water.
2. In combination with a hydro-pneumatic accumulator, a governing valve as
described for the purpose of regulating the escape of water in accordance with the
quantity received from pumps.
Dated this Fourth day of July 1200
JOHN SANDERS STEVENS.
CHARLES GEORGE MAJOR.
EDWIN CHARLES STEVENS.