Year: 1887

page_text: Date of Application, 5th May, 1887
Complete Left, 3rd Feb., 1888
Complete Accepted, 9th Mar, 1888
I JAMES YATE JOHNSON of 47 Lincolns Inn Fields in the County of Middlesex
Gentleman do hereby declare the nature of this Invention which has been com-
municated to me from abroad by François Auguste Souriau of Limoges in the
Republic of France of no Profession to be as follows :-
This Invention relates to a disappearing turret or shield suitable for fortified places
coast defences and ships of war. This turret is supported in a state of equilibrium
upon a plunger immersed in liquid as hereinafter described whereby the effect of
the weight is neutralised and the turret is enabled to be moved vertically by such
force as can be readily applied by manual labour without the aid of motive power
engines. The turret itself may be constructed with or without a cover or roof and its
sides or walls may extend over a portion only of its circumference thus reducing it to
a shield.
The plunger is completely immersed in a liquid contained in a tank in a well or
cavity formed by a deepening or extension of the pit in which the turret is worked.
The plunger is connected to the turret by supports which pass through a floor formed
by an external crown or ring completely fixed and a part which is capable of rotating
but does not move vertically.
This floor forms the bottom of the pit in which the turret works. The plunger is
guided at its lower end by a pivot and the turret is guided or supported laterally by
guides at the sides of the pit.
In order to produce the vertical or rising and falling motion which constitutes the
disappearing action of the turret a windlass is employed acting on a chain one
extremity of which may be attached to the turret the other extremity being attached
to the plunger-By winding up the chain in one direction or the other the turret may
be raised or lowered-Any other suitable mechanical device may be employed if
preferred. The turret likewise requires to partake of an angular motion that is to
Bay of a rotary motion upon its vertical axis-With this object a circular rack may be
provided in the moveable or rotating part of the floor in such a manner that a suitable
arrangement of gearing on the fixed part of the flooring enables the required rotary
motion to be produced.

page_text: The number of men required to work the disappearing turret may be still further
reduced by using a supplementary plunger which is alternately immersed and lifted
out of the liquid and serves to produce the alternate rising and falling motion of the
turrets automatically.
-
The additional or supplementary plunger consists of a cylindrical watertight crown
or cylinder placed upon the main plunger which is preferably made hollow or annular.
This crown is made of a height equal to the vertical movement of the turret and its
upper edge is exactly level with the surface of the liquid when the turret is down its
bottom being exactly level with the surface of the liquid when the turret is fully
elevated. This plunger is divided horizontally into two equal parts. The upper part
is made as light as possible and its volume is so calculated that when immersed it
exerts a sufficient upward pressure to set the turret in motion with the required
speed This pressure gradually decreases and finally ceases when the turret is half
way up but by this time the turret has acquired sufficient vis viva to carry it through
the other half of its travel. This vis viva must be neutralised by the time the turret
has reached the limit of its elevation in order to obviate a shock. With this object
the weight of the lower part is made exactly equal to the weight of the volume of
water that it displaces and its weight is uniformly distributed throughout its height.
When the turret is half way up the upper limit of the lower part is level with the
surface of the water; the turret then draws this part upwards but it is evident that
at the end of the second half of the ascent the weight of the lower part which is drawn
by degrees out of the water will gradually counterbalance and overcome the vis viva
of the turret its action being similar to that of the upper part but exerted in the
opposite direction. After the turret has reached the limit of its asconding motion the
relative actions of the parts are reversed; the weight of the lower part tends to move
the turret downwards and forces it through the first half of its descent wherein the
turret acquires a certain momentum or vis viva which it afterwards expends in pushing
the upper part downwards into the water.
This additional plunger thus overcomes the resistance due to inertia and the men
are simply required to overcome the resistance due to the friction.
The turret may be retained in its lowest position or in its highest position by means
of grippers provided with a catch or detent and which engage automatically with rings
or supports attached to the floor forming the bottom of the pit.
The crown forming the supplementary plunger is simply placed upon the main
plunger but is attached to a drum or cylinder connecting the turret with the said
main plungers, and if at any time it should be desired to separate the crown from the
plunger it is simply necessary to raise the turret and when in this position to attach
the crown to the floor by means of chains and rings and to take out the screws which
connect it to the cylinder.
It is evident that the form or shape of the plungers may be modified and that the
mechanism employed to effect the various movements connected with the disappearing
and directing may be differently arranged without affecting the principle of the
invention.
n
1 1

page_text: COME LEIE OLITICATION.
A Hydrostatic Disappearing Turret or Shield.
I JAMES YATE JOHNSON of 47 Lincolns Inn Fields in the County of Middlesex
Gentleman do hereby declare the nature of this Invention, which has been
communicated to me from abroad by François Auguste Souriau of Limoges in the
Republic of France of no profession 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 a disappearing turret or shield suitable for fortified places
coast defences and ships of war. This turret is supported in a state of equilibrium
upon a plunger immersed in liquid as hereinafter described whereby the effect of the
weight is neutralised and the turret is enabled to be moved vertically by such force
as can be readily applied by manual labour without the aid of motive power engines.
The turret itself may be constructed with or without a cover or roof and its sides or
walls may extend over a portion only of its circumference thus reducing it to a shield
or mantlet.
And in order that the said Invention may be fully understood I shall now proceed
more particularly to describe the same and for that purpose shall refer to the several
figures on the annexed sheet of drawings the same letters of reference indicating
corresponding parts in all the figures.
Figure 1 of the accompanying drawings represents a vertical section of a turret
arranged according to this Invention.
T is the turret proper which is supported by a float or plunger P' by the intervention
of vertical legs or supports S S. The plunger P is completely immersed in the liquid
contained in a tank Carranged directly under the turret in a well or subterranean
cavity formed by a deepening or extension of the pit in which the turret is concealed
when depressed. The supports S S pass through a floor or platform B A B formed
by a stationary external annular gallery B and a central circular part A which is
capable of rotating but does not move vertically. The plunger P is guided at its
lower end by a vertical pin or pivot L and the turret is guided or supported laterally
by guides G at the sides of the pit.
The plunger P being constructed in such a manner or of such a volume that the
weight of all the moveable parts is balanced by the pressure of the liquid upon the
sai plunger it will be readily understood that the force required to move the turret
vertically depends solely on the amplitude of this movement and the time employed
or in other terms on the speed to be imparted to the entire system and on the
resistance offered by the liquid in proportion to the surface immersed. It has been
ascertained by calculation that in practice the force to be exerted in this way is not
greater than what can be conveniently produced by men working at cranks and
toothed gearing.
In order to produce this vertical or upward and downward motion which constitutes
the disappearing action it suffices to arrange upon the platform A an ordinary
windlass (not shown-in the drawing) acting on a chain one extremity of which is

page_text: attached to the turret the other extremity being attached to the plunger. By winding
up the chain in one direction or the other the turret may be raised or lowered. Any
other suitable mechanical device may be employed in place of the windlass if
preferred.
The turret requires to partake of an angular motion that is to say of a rotary motion
upon its vertical axis in addition to the vertical motion. With this object a circular
rack F may be provided in the moveable floor A in such a manner that a suitable
arrangement of gearing on the fixed part B of the flooring enables the required rotary
motion to be produced imparted to the rack F and consequently to the floor A,
turret T and float or plunger P.
The number of men required to work the disappearing turret may be still further
reduced by using a supplementary plunger which is alternately immersed and lifted
out of the liquid and serves to a certain extent to cause the turret to move
automatically.
This arrangement is illustrated in vertical section in Figure 2 of the accompanying
drawing which differs from that.illustrated in Figure 1 with regard to the following
points only viz. The four legs or columns S which connect the turret with the
plunger in Figure 1 are replaced in Figure 2 by a hollow cylinder D of sheet metal
cut away at the base in such a manner as to form connections corresponding to the
legs S fig. 1. which slide in holes in the moveable or rotating floor A and connect the
cylinder D to a plunger P which is of annular form being made with a central
passage P through the centre. The additional or supplementary float or plunger
consists of a cylindrical watertight crown or cylinder E forming an annular trough or
chamber placed upon the main plunger P. This trough or chamber is made of a
height equal to the vertical movement of the turret and its upper edge is exactly level
with the surface of the liquid when the turret is down in its lowest position, the
bottom of the said trough being exactly level with the surface of the liquid when the
turret is fully elevated. This plunger is divided horizontally into two equal parts m
and n.
The part m is made as light as possible and its volume is so calculated that
when immersed it exerts a sufficient upward pressure to cause the turret to ascend
with the required speed. This pressure gradually decreases and finally ceases when
the turret is half way up but by this time the turret has acquired sufficient momentum
or vis viva to carry it through the other half of its travel. This momentum requires
to be neutralised or expended by the time the turret has reached the limit of its
elevation in order to obviate a shock. With this object the weight of the lower part n
is made exactly equal to the weight of the volume of water that it displaces and its
weight is uniformly distributed throughout its height. When the turret is half way
up the upper limit of the part n is level with the surface of the water, the turret then
draws this part n upwards but it is evident that at the end of the second half of the
ascent the weight of the lower part n which is drawn by degrees out of the water will
gradually counterbalance and overcome the vis viva or momentum of the turret its
action being similar to that of the upper part m but exerted in the opposite direction.
After the turret has reached the limit of its ascending motion the relative actions of
the parts m and n are reversed; the weight of the lower part n tends to move the
turret downwards and forces it through the first half of its descent wherein the turret
acquires a certain momentum or vis viva which it afterwards expends in pushing the
part m downwards into the water. These movements would evidently be repeated
indefinitely but for the resistance resulting from friction. The parts m and n acting
with a regularly increasing or decreasing force their maximum force must be double the
constant force which would be required to produce the same result. This additional
float or plunger thus enables the resistance due to inertia to be readily overcome
the men being simply required to overcome the resistance due to the friction of the
various parts.
It is sufficient in fact to keep the turret in its lowest position when the tank is filled
for the first time the chamber E is then immersed up to its upper edge.
When in this position and at rest the turret is held down or retained in its lowest
position against the pressure of the plunger by means of grippers or hooks i provided

page_text: eyes o.
with a pivoted catch or trigger and which engage automatically with rings or eyes o
attached to the floor A the weight of the latter being sufficient to overcome the
tendency of the plunger to lift the turret. In order to cause the turret to rise to
its highest position it is simply necessary to disengage the hooks or grippers i from the
The buoyancy of the float or plunger P combined with that of the part m
then forces up the turret to its highest position where it is retained by hooks which
engage automatically with supports K. To lower the turret the hooks jare
disengaged from the supports K whereupon the turret is immediately caused to
descend by the weight of the float P acting in combination with that of the part n of
the annular part or chamber E.
To work the turret in a continuous manner the arms of both sets of hooks must be
secured or held out of action. To cause the turret to stop in one position the hooks
corresponding to the other position must be held out of action.
The annular trough or chamber E is simply placed upon the plunger P and is
attached to the cylinder D so that at any time it should be desired to separate the
chamber from the plunger it is simply necessary to raise the turret and when in this
position to attach the chamber to the floor A by means of chains and rings and to
take out the screws which connect it to the cylinder D.
It is evident that the form or shape of the floats or plungers may be modified and that
the mechanism employed to effect the various movements connected with the
disappearing and directing may be differently arranged without affecting the principle
of the invention.
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. A disappearing turret or shield whose weight is balanced by a plunger or float
immersed in liquid or fluid and enabling the vertical movements of the turret to be
produced without the employment of any greater effort or force than that which can
be conveniently produced by the strength of men applied to an ordinary winch or
other like mechanism substantially as hereinbefore described with reference to
Figure 1 of the accompanying drawings.
2. In combination with a float or plunger such as that referred to in the preceding
claiming clause a second float or plunger alternately immersed in and lifted out of the
liquid and serving to produce and control the alternating vertical movements of the
turret or shield substantially as herein before described with reference to Figure 2 of
the accompanying drawings.