Improvements in Pressure Gauges for Air, Water, and other Fluids.
Year: 1898

page_text: Date of Application, 1st Mar., 1898
Complete Specification 1 eft 1st Dec 1808 Accented 21ct lan
4000
PROVISIONAL SPECIFICATION.
Improvements in Pressure Gauges for Air, Water, and other Fluids.
I, CHARLES LAURENCE BURDICK, of No. 30, Memorial Hall, Farringdon Street,
in the City of London, Artist, do hereby declare the nature of this invention to
be as follows:
My invention relates to gauges which are useful for registering the pressure
of any fluid such as air, water or the like, and which are capable of being made
of comparatively few and simple parts and of small dimensions.
According to my invention I construct the gauge of an inner tube and an
outer tube or shell and these two tubes are connected together at one end for
instance by means of a body part or base piece. The outer tube is preferably
made of metal or other suitable material, while the inner tube is made of india
rubber or other flexible or elastic material and is closed at the free end furthest
from the source of pressure for instance by being squeezed between the internal
wall of a conical cap or washer and a correspondingly formed cone provided with
a screwed end and nut. The body piece or support is for instance provided with
a conical. recess into which fits a correspondingly formed cone the end of which
is screwed into the said base piece and the end of the inner tube is clamped in
the recess by the cone. It is however evident that the flexible tube may be closed
at one end and connected at the other end to the body piece in any other suit-
able manner. The inner tube is cylindrical or thereabouts and in order to sup-
port it and to prevent it from binding against the inside of the outer tube it is
provided with a helical coil of wire or the like. The helical coil of wire is
attached at one end to the base piece by a set screw or otherwise and at the
other end to the cap so that when the tube expands under pressure of the fluid
contained therein, which enters by an opening in the base piece, a movement
is given to the free end of same and as that end is provided with a pointer or
index suitably consisting of the end of the helical spring bent to shape, the
amount of pressure is recorded on an index plate or scale on or forming part of
the outer tube, it being understood that if the latter be made of metal there is
a slot through which the index projects. The slot is helical and the reason for
this is that as the tube expands it tends to lengthen and with it the helical
spring but the latter is also simultaneously constrained to uncoil and conse-
quently to twist, thus the pointer moves in a helical path or thereabouts, but if
desired the slot may be longitudinal and the index or pointer may take a similar
path. The gauge may conveniently be provided with a screwed nozzle or the
like for attachment to the supply pipe for the compressed air or other fluid and
with a female coupling or the like for attachment for instance to the nozzle of
the valve of a cycle trye or other object to be supplied with compressed
air. The outer tube is conveniently covered with another tube of more or less
transparent material to protect the index or pointer from injury and to keep the

page_text: interior free from dirt damp and the like, and the outer ends of the two last
mentioned tubes are closed by means of a cap or stopper.
According to another modification the flexible or elastic tube is slipped over
another tube which serves as a body part or support and it is secured thereon
The
by a whipping or binding at each end or in any other convenient manner.
elastic tube is in this case surrounded by two volute springs of which two of the
ends come together and may if desired be joined. It is however evident that if
desired helical springs may be employed. These ends form the index and show
through a slot in the outer tube, the edges of which slot are marked with a scale
pres-
and figures to suit the position of the index when the gauge is under different
sures. The gauge is conveniently provided with ends which are screwed in or
otherwise attached to for example the tube forming the body part by means of
nuts. Air is forced in through the nozzle and past a valve which may be of lip-
form or of other suitable construction. There is a hole in the tube serving as
body part through which the air passes and forces the elastic tube out to more
or less fill the volute springs causing them to untwist and by their ends shew the
pressure in the gauge for as aforesaid the ends of the latter form the index and
their movement when taken together practically amounts to a movement in the
arc of a circle. There are couplings for attaching the gauge to the source of
compressed air and the apparatus intended to be supplied therewith.
According to another modification the tube forming the body part is. closed at
one end and there are suitable connections at the other end for the source of
compressed air and the apparatus intended to be supplied therewith. In order to
prevent variations of pressure when pumping with a single acting pump for
instance and to retain the index at the point on the scale indicating the pressure
obtained at the end of the working stroke I provide a valve consisting for
instance of a tube closed at one end and having a hole at the side covered by a
piece of india rubber tube. The outside tube or shell may also be made of metal
instead of transparent material and be provided with a slot to correspond with
the slot in the afore mentioned outer tube. The shell is attached to a movable
end and the latter has a screwed hole the bottom of which forms a valve seat
being provided with a washer against which the extremity of the outer screwed
end of the tubular body part takes when the end of the shell is screwed up. The
tubular body part and the outer tube are as before described screwed or otherwise
fixedly attached to the base piece.
Doted this inst lov of March 1898
JENSEN & SON,
77, Chancery Lane, London, W.C., Patent Agents.
Improvements in Pressure Gauges for Air, Water, and other Fluids.
I, CHARLES LAURENCE BURDICK, of No. 30, Memorial Hall, Farringdon Street,
in the City of London, Artist, 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: --
My invention relates to gauges which are useful for registering the. pressure
of any fluid such as air, water or the like, and which are capable of being made
of comparatively few and simple parts and of small dimensions.
. Figure 1 of the accompanying sheet of drawings represents one form of gauge
in longitudinal section.

page_text: Figure 2 is an elevation thereof.
Figure 3 is a longitudinal section of a modified construction.
Fig. 4 is an elevation thereof.
Fig. 5 is a longitudinal section of another modification.
Fig. 6 is a longitudinal section of yet another modification and
Fig. 7 is a transverse section thereof on the line X X Fig. 6.
According to my invention as shown in Figs. 1 and 2 I construct the gauge of
an inner tube A and an outer tube or shell B and these two tubes are connected
together at one end for instance by means of a body part or base piece C. The
outer tube B is preferably made of metal or other suitable material while the
inner tube A is made of india rubber or other flexible material and is closed at
the free end furthest from the source of pressure for instance by being squeezed
between the internal wall of a conical cap or washer D and a correspondingly
formed cone E provided with a screwed end and nut F. The body piece or
support C is for instance provided with a conical recess into which fits a corres-
pondingly formed cone H the end of which is screwed into the said base piece
and the end of the inner tube is clamped in the recess by the cone. It is how-
ever evident that the flexible tube may be closed at one end and connected at
the other end to the body piece in any other convenient manner. The inner
tube A is preferably cylindrical or thereabouts and in order to support it and
to prevent it from binding against the inside of the outer tube it is provided
with a helical coil of spring wire Gor the like. In this construction the helica!
coil of wire G is attached at one end to the base piece C by a set screw C¹ and
at the other end to the cap D so that when the tube A expands under pressure of
the fluid contained therein which enters by the opening C3 a movement is given
to the free end of same and as that end is provided with a pointer or index G¹
suitably consisting of the end of the helical spring G bent to shape, the amount
of pressure is recorded on an index plate or scale on or forming part of the outer
tube B, it being understood that if the latter be made of metal there is a slot B¹
through which the index G₁ projects. It will be seen that the slot is helical or
slanting and the reason for this is that as the tube A expands it tends to
lengthen and with it the helical spring G but the latter is also simultaneously
constrained to uncoil and consequently to twist, thus the pointer moves in a
helical path or thereabouts. The gauge may conveniently be provided with a
screwed nozzle H or the like for attachment to the supply pipe for the com-
pressed air or other fluid and with a female coupling H or the like for attach-
ment for instance to the nozzle of the valve of a cycle wheel tyre or other object
to be supplied with compressed air. The outer tube B is conveniently covered
with a tube B2 of more or less transparent material to protect the index or
pointer G¹ from injury and to keep the interior free from dirt damp and the
like. The end of the tube B is closed by means of a cap or stopper I.
Figures 3 and 4 show a gauge constructed of a flexible or elastic tube A made
of rubber or other suitable material or fabric which tube is slipped on a tube D'
serving as a body part or support and secured thereon by a whipping or bind-
ing D2 at each end as shown or in any other convenient manner. The elastic
tube A is in this case surrounded by two volute springs G2 G3, the respective
ends GG of which come together, and may if desired be joined by a rivet Go
but it is evident that if desired helical springs may be. employed. These
ends G* G³ form the index and show through a slot B in the tube B, the edges
of which slot are marked with a scale and figures to suit the position of the index
when the gauge is under different pressures. The gauge is conveniently provided
with ends C3 and I which are screwed in or otherwise attached to, for example,
the tube or body part D' by means of nuts D and D. Air is forced in through
the nozzle H and past the lip valve H¹ (or any other suitable construction of
valve may be used). There is a hole D in the tube D¹ through which the air
passes and forces the elastic tube A out to more or less fill the volute springs
causing them to untwist and by their ends G+ G³ show the pressure in the gauge

page_text: for as aforesaid the ends G4 G5 form the index and their movement, when taken
together, practically amounts to a movement in the arc of a circle. It is also
evident that the tube A may if desired correspond when not under pressure to
the internal form of the volute springs instead of being normally cylindrical.
H is the coupling for attaching the gauge to the nozzle of the valve of the tyre
or other apparatus to be supplied with air and the gauge may suitably be pro-
vided with a shell or tube 12 of transparent material.
or.
to
Figure 5 shows a modification which in construction is a combination of those
constructions described with reference to Figures 1, 2, 3 and 4 only the end I³
forms a valve seat being provided with a washer I against which the screwed
end De takes when the end 13 is screwed up. The tubular body part D provided
with a hole D is screwed into or otherwise fixedly attached to the base piece C
air is admitted by the coupling H and the passage C³ communicates both with
the gauge part proper and the nozzle H5 for attachment to the valve of the tyre
or other apparatus to be supplied with air. In order to prevent variations of
pressure arising when pumping with a single acting pump for instance and
retain the index at the point on the scale indicating the pressure obtained at the
end of the working stroke, I provide a valve consisting for instance of a tube H¹
closed at one end and having a hole H³ covered by a piece of india rubber He
The outside tube or shell B2 may also be made of metal instead of transparent
material and provided with a slot B³ to correspond with the slot B' in the
tube B. The tube B2 is attached to the end I³ so that when the latter is turned
to release the air from the interior of the tube D¹, the opening or slot B³ does
not register with the slot B¹ and consequently the interior of the gauge is kept
free from dust or dirt. The base or other part is preferably provided with a
stop of any suitable construction to prevent the tube B2 from being inadvertently
removed. Or if desired either the tube B2 or the tube B may be made of trans-
parent material as described with reference to the preceding figures.
Figure 6 shows a gauge which is very similar in construction to that described
with reference to Figures 3 and 4, the principal difference being that the
springs G 2nd G³ are mounted on or attached to thimbles E¹ and E³ respectively
which are held fast in position when the ends 03 and I¹ are screwed up.
Figure 7 shows the way I prefer in some cases to mount the tube D in the
ends C³ and I¹ (see also Figure 6) that is to say the tube D¹ is mounted eccen-
Arically for the purpose of allowing of the use of as small a tube B as possible
for it is evident that the springs in expanding, expand mostly at their free ende
thus going further away from the centre of the tube D' and if room is to be
left for expansion it naturally follows that it is preferable to leave it at that part
or parts where most of the expansion takes place. It will also be apparent that
I may if desired use tubes of any other section than round.
Although I have described my invention as being applicable for attachment to
both the source of compressed air or other fluid such as an inflater and to the
apparatus for containing such compressed air such as
evident that it may if desired be made to be applicable to either the source of
a pneumatic tyre it is
compressed air or to the said apparatus all as found most convenient or it may
be permanently attached or connected to a tube between the source of compressed
air and the apparatus to be supplied.
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 pressure gauge consisting of a body part or support, a flexible or elastic
tube re-inforced or supported by a spring or springs, an index or pointer, a

page_text: scale and means for connection to the source of compressed air or other fluid
and
or
to the receptacle to be filled with said fluid substantially as set forth.
2. A pressure gauge consisting of a tubular body part or a support, a flexible
or elastic tube supported and surrounded by a helical spring having an index or
pointer moving in an approximately helical path, a scale and means for con-
and
nection to the source of compressed air or other fluid to the receptacle to
or
be filled with said fluid substantially as described and shown.
3. A pressure gauge consisting of a tubular body part or a support, a flexible
or elastic tube surrounded by two helical or volute springs having an index or
pointer moving approximately in the arc of a circle, a scale and means for con-
and
nection to the source of compressed air or other fluid' to the receptacle to be
or
filled with said fluid substantially as described and shown.
4. The construction of pressure gauge substantially as described with reference
to Figures 1 and 2.
5. The construction of pressure gauge substantially as described with reference
to Figures 3, 4, 6 and 7.
6. The construction of pressure gauge substantially as described with reference
to Figure 5.
Dated First day of December 1898.
JENSEN & SON,
77, Chancery Lane, London, W.C., Patent Agents.