Improvements in or connected with Brakes, Buffers, Accumulators, and other like Apparatus in which a Fluid is Alternately Compressed and Expanded.
Year: 1889

page_text: Date of Application, 24th Apr., 1889
Complete Specification Left, 17th Jan., 1890-Accepted, 22nd Feb., 1890
PROVISIONAL SPECIFICATION.
Improvements in or connected with Brakes, Buffers, Accumulators,
and other like Apparatus in which a Fluid is Alternately
Compressed and Expanded.
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 Jacques Antoine Creuze de Latouche of 260 Boulevard
St. Germain Paris in the Republic of France Engineer to be as follows
One of the chief disadvantages connected with pneumatic and hydro pneumatic
brakes buffers and accumulators arises from the rapid variations in the tension of the
gaseous spring or elastic medium which take place when the volume increases or
diminishes and render the adjustment or regulation extremely difficult. In order to
remove this disadvantage recourse has been had to the construction of chambers or
reservoirs of large capacity relatively to the body of the pump but this renders
the apparatus cumbersome costly and difficult of charging. When in place of the
permanent gases usually employed a fluid is introduced that is liquifiable at a given
pressure at ordinary temperature and care is taken that this fluid is present in such
quantity or volume that a portion thereof constantly remains in a liquid condition
and another portion likewise remains in a gaseous condition under all the variations
in the capacity of the containing chamber or reservoir the pressure or resistance
remains constant or is solely influenced by the calorific phenomena resulting from
the transition of a portion of the fluid from the liquid to the gaseous condition
and vice versa during the modifications in the volume or capacity of the chamber.
If these transitions succeed one another with such rapidity that the loss of heat-
through the walls of the chamber may be neglected the force absorbed during the
compression is almost completely recovered during the expansion otherwise there is a
certain amount of waste.
On the other hand the variations in the pressure will always be relatively small if
the weight of fluid which remains liquid at the moment of maximum expansion is
somewhat large relatively to the weight of aeriform or gaseous fluid present at
the same moment. As the specific weight of the liquid is always very considerable
relatively to that of the gas estimated by the same unit the space filled by the
liquid is always very small relatively to the variations in the volume of the reservoir
and the increase in the dimensions of the apparatus is reduced to a minimum.
The present invention consists in the novel employment of these non permanent
or liquefiable gases in brakes buffers accumulators and other like apparatus in which
a fluid is alternately compressed and expanded.
The invention is applicable to most existing brakes such as are ordinarily employed
and the improved arrangement may be employed with advantage in the place of the
counterweights commonly employed for balancing or compensating the weight of any
heavy object which requires to be frequently moved into different positions with a
small expenditure of force.
For example the weight may be suspended on cords passing over pulleys and con-
nected to a plunger working vertically in a hollow cylinder closed at its upper end.
The inner and upper side or face of the plunger is provided with a cavity or hollow
for the reception of the liquid portion of the elastic medium or liquefiable gas with
which the cylinder is charged the apparatus being so adjusted that this liquid portion
possesses considerable weight even when the plunger is at the bottom its stroke and
the capacity of the cylinder is at its maximum.
It is evident that the construction of the apparatus may be varied considerably
according to the nature of the work to be performed.

page_text: The cylinder or chamber may be closed at its lower end the piston or plunger
working vertically or in any other direction.
A greater degree of resistance may be obtained with combined hydraulic and
gas brakes by reducing the capacity of the gas chamber and separating the water
or other liquid from the fluid (liquified gas) by an intermediate piston provided
on its surface with a cup or cavity for the reception of the liquified portion of the
fluid.
In this case pistons or plungers are caused to act upon water or other liquid
which transmits the pressure through the aforesaid intermediate piston to the liqui-
fiable gas. This arrangement may be combined with any suitable system of rubber
or other springs and automatic or other valves controlling the movements of the
liquids or gases. The chamber containing the liquifiable gas may form part of a
hollow plunger working in the cylinder or chamber containing the whole or part
of the water or other liquid used to transmit the pressure. According to another
arrangement the liquifiable gas is contained in an annular chamber made in two
parts constructed to slide telescopically one in the other and communicating with
rams or plungers or pistons or a plunger or plungers combined with a piston or
pistons acting on the gas or elastic medium employed, one of the parts of the annular
chamber being fixed and the other connected to the weight or the like to be balanced
or compensated. These arrangements or constructions of the apparatus are merely
given as examples for the sake of explaining the principles of the invention.
Dated this 24th day of Anril 1889
J. H. JOHNSON & Co.,
47, Lincoln's Inn Fields, London, W., Agents.
COMPLETE SPECIFICATION.
Improvements in or connected with Brakes, Buffers, Accumulators,
and other like Apparatus in which a Fluid is Alternately
Compressed and Expanded.
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 Jacques Antoine Creuze de Latouche of 260 Boulevard
St. Germain Paris in the Republic of France Engineer and in what manner the same
is to be performed to be particularly described and ascertained in and by the following
statement :-
One of the chief disadvantages connected with pneumatic and hydro pneumatic
brakes buffers and accumulators arises from the rapid variations in the tension of the
gaseous spring or elastic medium which take place when the volume increases or
diminishes and render the adjustment or regulation extremely difficult. In order to
remove this disadvantage recourse has been had to the construction of chambers or
reservoirs of large capacity relatively to the body of the pump or press but this renders
the apparatus cumbersome, costly and difficult of charging.
When in place of a permanent gas a fluid is introduced that is liquifiable at a given
pressure at ordinary temperatures and care is taken that this fluid is present in such
quantity or volume that a portion thereof constantly remains in a liquid condition and
another portion likewise remains in a gaseous condition under all the variations in the
capacity of the containing chamber or reservoir the pressure or resistance remains
constant or is solely influenced by the calorific phenomena resulting from the transition
of a portion of the fluid from the liquid to the gaseous condition and vice versa during
the modifications in the volume or capacity of the chamber.
If these transitions succeed one another with such rapidity that the loss of heat
through the walls of the chamber may be neglected the force absorbed during the
compression is almost completely recovered during the expansion otherwise there is a
certain amount of waste.
On the other hand the variations in the pressure will always be relatively small if
the weight of fluid which remains liquid at the moment of maximum expansion is

page_text: somewhat large relatively to the weight of aeriform or gaseous fluid present at the
same moment. As the specific weight of the liquid is always very considerable
relatively to that of the gas estimated by the same unit, the space filled by the liquid
is always very small relatively to the variations in the volume of the reservoir and
the increase in the dimensions of the apparatus is enabled to be reduced to a
minimum.
The present invention consists in the novel employment of these physical properties
of non permanent or liquefiable gases in pneumatic or hydro pneumatic brakes,
buffers, accumulators or compensators employed in connection with gun mountings
or artillery.
In apparatus of this description the permanent gas such as the air commonly
employed as the spring or elastic medium is replaced by a fluid capable of liquefying
under suitable pressure at the ordinary temperature care being taken to charge the
apparatus in such a manner that the fluid therein is always partly in a liquid and
partly in a gaseous condition.
By these means a practically constant resistance to compression is obtained.
The invention is applicable to most existing brakes of this class such as are ordinarily
employed and the improved arrangement may be employed with advantage in the
place of the counterweights commonly employed for balancing or compensating the
heavy weights which require to be frequently moved into different positions with a
small expenditure of force.
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 is a diagram representing by way of
example an arrangement in which a weight P is suspended on cords or chains d
passing over pulleys c and connected by a bar D working in guides on a support C
to a plunger B in a fixed hollow cylinder or pump body A closed at its upper end and
attached to the stationary support C. The cylinder A is charged with a fluid, or
liquefiable gas under such pressure that the fluid in the upper part of the cylinder is
in a gaseous condition and a portion of the fluid in a liquid condition accumulates
at L in a cavity b provided in the inner and upper side or face of the plunger or
piston B the apparatus being so adjusted that a certain weight of liquid is present
even when the plunger B is at the bottom of its stroke and the capacity of the cylinder
is consequently at its maximum.
When the piston B is moved the sole effect produced (the calorific phenomena
arising from the change of form of the fluid being left out of account) is that the
quantity of liquid or proportion of fluid in the liquid state is increased or diminished
without modifying the internal tension and consequently without modifying the action
on the bar D.
The arrangement of the apparatus employed in carrying out the invention in
practice may evidently be modified according to the requirements and circumstances
of each case. Figure 2 represents a fluid (gas and liquid) brake or compensating
buffer providing a practically constant resistance and in which the liquid collects
at the bottom of the cylinder or pump body A beyond the lowest point reached by
the piston.
The action of this apparatus will be readily understood on reference to the drawing
the corresponding parts being marked with the same letters of reference as in
figure 1.
In order to obtain more considerable resistances the system may be applied to
hydro pneumatic brakes by employing a gas chamber of smaller capacity and
separating the liquid from the fluid or liquified gas by a piston provided on its
apper surface with a cup or cavity for the reception of the liquefied portion of
the fluid.
This arrangement or process also enables a series of independent apparatus such as
brakes, compensators, substitutes for counter weights, buffers and the like to be placed

page_text: in communication with one reservoir or chamber containing the regenerating fluid
without causing the action of some or any of these apparatus to affect the action
of the others the internal pressure being practically constant owing to the change
in the form or condition of the fluid corresponding to the variations in the
pressure.
According to the arrangement illustrated in figure 3 the weight P is halanced
by an apparatus constructed with a pump body A forming an annular gas chamber
and a piston B of annular form in plan or section sliding therein leaving the
axis or central part free or open. The liquid accumulates in the piston at L.
The cord or connection d in this arrangement can be attached directly to the
centre of the upper surface of the end or bottom of the piston B in place of being
attached to a transverse bar as in the arrangement illustrated in figure 1.
The arrangement represented in figure 3 also comprises two independent brakes F
and F, the brako F being constructed with a piston and piston rod and the brake F¹
with a plunger or ram. Both of these brakes communicate with the gas chamber A
of the compensator. These three apparatus are capable of acting independently and
at the same tension the resistance or power of each apparatus being proportionate to
the area of its piston.
It is evident that the number of pump bodies or brake cylinders communicating
with the central chamber or with one another may be increased as required thus
greatly simplifying the charging of the entire combination.
Having now particularly described and ascertained the nature of the said Inven-
tion and in what manner the same is to he performed I declare that I do
not claim broadly the abstract principles involved in my invention but what I
claim is.
First The novel application, as the elastic medium or spring in pneumatic or
hydro pneumatic brakes, buffers accumulators or compensators for gun mountings or
artillery, of a fluid which is constantly maintained under sufficient pressure to be
partially liquefied at the ordinary temperature in all positions that the brake or
apparatus is called upon to assume substantially as hereinbefore explained with
reference to the accompanying drawings.
Second Pneumatic or hydro pneumatic brakes, buffers accumulators or com-
pensators specially constructed for gun mountings or artillery in accordance with my
invention as bereinbefore set forth.
Dated the 17th day of January 1890.
J. H. JOHNSON & Co.,
Agents.