A New or Improved Membrane for Indicating and Recording Devices for Computing the Pressure or Volume of Liquids.
Year: 1896

page_text: Date of Application, 31st July, 1896
Complete Specification Left, 28th Apr., 1897-Accepted, 31st July, 1897
A New or Improved Membrane for Indicating and Recording Devices
for Computing the Pressure or Volume of Liquids.
I WALTER ALFRED BARLOW of 7 John Street, Bedford Row London, W.C.
Consulting Engineer and Patent Expert, do hereby declare the nature of this
invention to be as follows:-
This invention relates to a new or improved membrane for indicating and recording
devices for computing the pressure or volume of liquids the object being to
transmit the variations of pressure or volume from the interior of the recipient to
the exterior thereof, as will now be more fully described.
The said transmission membrane consists of a cylindrical tube of india rubber and
a spiral traction spring of about equal resistance, and the rubber cylinder is
restraining in its action whilst the spiral spring is arranged to set up expansion so
that in juxtaposition there is secured together there is a combined effect which is
restraining, expansive and elastic.
The parts so constituted are lodged in a tube of metal or the like, to resist tendency
to sidewise movement or flexion.
In applying this membrane in order that it may contain a fluid there is applied
to one end of the india rubber tube a plain stopper on which is a ligature or binding.
This ligature is made in such wise as to maintain the spring with the binding wire
between the spirals thereof the spiral spring being outside the india rubber tube
and covering the stopper.
A cap is put over the end of the stopper piece and coupled by a screw, that is
the stopper end may have a screw-threaded projecting neck engaging with an
internal screwed recess in the cap so ensuring guidance within the external tube
aforesaid, and admitting of the membrane gliding on expansion or contraction
within said external tube.
The cap may by means of a screw threaded neck attachment be connected with
any system of indicator device or instrument the union being made if required
within a stuffing box.
A similar fitting but tubular within a stuffing box will be set up at the opposite
end of the membrane, and fitted to a tube in connection with the fluid the pressure
or volume whereof has to be computed.
If the pressure is external the spiral will be placed interiorly of the india rubber
tube.

page_text: A New or Improved Membrane for Indicating and Recording Devices
for Computing the Pressure or Volume of Liquids.
A communication from abroad by G. DORIAN, Constructional Engineer, of Paris, in
the Republic of France.
I, WALTER ALFRED BARLOW of 306 High Holborn, London W.C. Consulting
Engineer and Patent Expert, formerly of 7 John Street, Bodford Row, London, W.C.
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 a new or improved membrane for indicating and recording
devices for computing the pressure or volume of fluids.
This membrane is designed to act conformably to and to transmit variations of
pressure or volume of fluids exteriorly of the receptacle containing such fluids.
The construction is based upon the combination of a tube or cylinder of india-
rubber (as indicated in section Fig. 1) and of a coiled traction spring (see Fig. 2).
These two elements have the property of being elastic, the india-rubber tube,
furthermore, being "fluid-tight" and the spring resistant. Placed one within the
other and being brought together at their ends there is formed an organ having the
three qualities, indispensable in an indicating membrane; that is, impermeability to
the passage of fluids (æriform, gaseous or liquid) elasticity, and resistance.
When the relation between the length and diameter of this membrane is excessive,
it is enclosed in a cylinder or tube (as indicated in sectional view Fig. 3) in which
it shall be free to play, the object of said outer or enclosing tube being to prevent
flexion or sideway play of the membrane relatively to its longitudinal axis.
Fig. 4, represents in central longitudinal section a fitting of the said membrane
for practical purposes.
C, is the india-rubber tube, terminated at one end by a solid plug A, a ligature
securing the two together. In similar manner the other end of the india-rubber
tube C, receives the plug B, which last, however, has a piercing or hole therein
longitudinally thereof.
R, is a coiled spring, surrounding the impermeable tube C, the lower end of said
spring R, having a screw-nut on the lower spirals whereby said spring R is there
retained, whilst at its other extremity it is securely attached to the tubo C, by the
interposition of the spirals with the binding wire L employed to secure the solid
plug A.
The whole is set into a stuffing-box S, surmounted by the tube T, and any suitable
packing (plastic or fibrous) disposed in said box S, will serve to hermetically close
the lower ends of the india-rubber tube and spring between the nut E and the screw
-cap of the box S, whilst the pierced plug B, extends below.
The spring R, has free play in the tube T, and will readily elongate or contract
with variations of internal pressure. The piece K fitted above the membrane is
equally free to rise and fall in the tube T, whilst ensuring the concentricity of the
parts. The piece K may be provided with a screw threaded plug as shown on the
outer end thereof or as may be convenient for transmitting beyond the tube T,
the movements of the membrane.
The hollow plug B, will be connected by tube or otherwise as required, to conduct
the fluid (the pressure or volume whereof has to be computed) into the membrane.
The tube T, as before observed, is requisite when the relation of the length to the

page_text: diameter of the membrane is excessive, otherwise both the tube T, and the piece K,
may be eliminated from the combination.
The membrane as represented in Fig. 4, of the drawings is arranged to receive
the fluid which actuates it interiorly, but in cases where the action of the fluid is
exerted externally the constituent elements will be inversely disposed; thus, the
spring R, will be lodged in the rubber tube, and, where the tube T is requisite, it
would be placed inside the convolutions of the spring.
The section of the wire of the spiral springs is represented as of round section,
but it may be square rectangular or otherwise. When it is found requisite to operato
the membranes of great length the special spring may be replaced by two others of
flat section with the spirals alternately disposed so that the one may cover-joint or
lap with the other.
The cases for the employment of this membrane are numerous, whereof for
example are those wherein the apparatus is employed in regulating pressure or
temperature.
Advantages of this membrane over others already known may be enumerated
as follows:
1. Its action may easily be equal to twenty per cent. of its length.
2. Its power being proportional to the pressure received per unit of its transverse
section, whatever same may be, is solely a question of dimensions.
3. The simplicity of the elements renders its construction easy and economical.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same may be performed I declare that what I
claim is :-
A membrane composed of two elements consisting of a tube of elastic and fluid-
tight material and a metallic spring, elastic longitudinally, and transversely resistant
such two elements being retained one within the other and brought together and
united at their extremities, combined, constructed and operating as and for the
purpose herein set forth and illustrated by the accompanying drawings.
17005
IZANGU ZUMI AULIN
WALTER A. BARLOW,
306 High Holborn, London, W.C., Applicant.