Improvements in Instruments for Recording and Registering Speeds or Pressures.
Year: 1893

page_text: Date of Application, 3rd May, 1893
Complete Specification Left, 3rd Feb., 1894-Accepted, 24th Mar., 1894
PROVISIONAL SPECIFICATION.
Improvements in Instruments for Recording and Registering Speeds
or Pressures.
I EDGAR CONISTON MILLS of No. 12 Victoria Buildings, Manchester in the
County of Lancaster, Engineer do hereby declare the nature of this invention to
be as follows:-
My present invention relates to that class of instruments for recording speeds and
pressures for improvements in which Letters Patent No. 8010 of the year 1888 and
No. 19976 of the year 1890 were granted to me.
The apparatus for receiving the fluctuations of air pressure above or below the
atmosphere and actuating the marker was described and illustrated in the Specifica-
tion of the former invention as a fluid syphon vessel forming no part of the said
invention.
My present invention consists of a flexible sheet diaphram of elastic or non-elastic
india-rubber, or of oiled silk or other suitable material to receive the said fluctuations:
of pressure. One surface of the diaphragm is exposed to the atmosphere, and the
other to the pressure to be recorded. The said pressure may be above or below
the atmospheric pressure, and it may be produced by the fan described in the
Specification referred to for the purposes of recording speeds and variations of'
speeds, or it may be the pressure of gas, or of ventilating air in mines, or of air for
blast furnaces or any other suitable pressures requiring to be recorded.
The diaphragm which is preferably circular is attached at its outer edge to the
sides or edge of a vessel having an opening connected with the pressure to be
recorded. It is constructed with a large amount of "slack," and by means of a
central disc or discs its movements are imparted to a vertical rod or spindle to which
the marker is attached. Suitable resistance to the movement of the diaphragm is
supplied by a long tension spring, or two such springs may be attached to a cross-
bar bearing upon or attached to the upper part of the spindle for pressure above
the atmosphere, and for pressure below the atmosphere a similar tension spring or
springs is or are applied to pull the spindle or cross-bar upwards either by direct
attachment or by means of a cord or chain or their equivalent passing over a pulley,
or by means of levers.
In cases in which the pressure is sometimes below and sometimes above the
atmosphere I use two or four such springs in combination and adjust them so that
the zero of impulse in either direction shall he reached at the position and moment
of atmospheric pressure being obtained.
Dated this 2nd day of May 1893
EDGAR CONISTON MILLS.
COMPLETE SPECIFICATION.
Improvements in Instruments for Recording and Registering Speeds
or Pressures.
I EDGAR CONISTON MILLS of No. 40 Victoria Buildings, Manchester in the
County of Lancaster, Engineer 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 present invention relates to that class of instruments for recording speeds and

page_text: pressures for improvements in which Letters Patent No. 8010 of the year 1888 and
No. 19976 of the year 1890 were granted to me.
The apparatus for receiving the fluctuations of air pressure above or below the
atmosphere and actuating the marker was described and illustrated in the Specifi-
cation of the former invention as a fluid. syphon vessel forming no part of the
said invention.
My present invention consists of a flexible sheet diaphragm of elastic or non-
elastic india-rubber or of oiled silk or other suitable material to receive the said
fluctuations of pressure. One surface of the diaphragm is exposed to the atmo-
sphere and the other to the pressure to be recorded. The said pressure may be
above or below the atmospheric pressure and it may be produced by the fan
described in the Specification referred to for the purposes of recording speeds
and variations of speeds, or it may be the pressure of gas, or of ventilating air
in mines or of air for blast furnaces or any other suitable pressures requiring to
be recorded.
In the accompanying drawings"
Fig. 1. represents my invention as applied to pressures above that of the
atmosphere.
Fig. 2. represents my invention as applied to pressures below that of the
atmosphere.
The flexible diaphragm A which is preferably circular and of conical form is
attached at its outer edge to the sides or edge of the vessel B having an
opening connected with the pressure to be recorded. It is constructed with a
large amount of "slack" and by means of a large central disc C to the edges
of which it is secured its movements are imparted to a vertical rod or spindle D
to which the marker is attached by the rod d. The spindle D simply rests
upon the inverted cone central recess c formed on the disc C by the centre
point d of the spindle D. Suitable resistance to the movement of the diaphragm
is supplied by a long tension spring or springs as shewn at E E Fig. 1. They
are attached to a crossbar F bearing upon the upper part of the spindle D
in the case of pressures above the atmosphere. The spindle D is hollow to
obtain lightness thus reducing inertia to secure sensitiveness and it is guided in
two positions by the three antifriction rollers g. whose bearings are carried by
the fixed brackets h, h, i is a wire yoke embracing D and serving to maintain
the disc C in a horizontal position.
The springs E E can be adjusted by the screws e and nuts e¹.
In the case of pressures below the atmosphere similar tension springs are used
as illustrated in Fig. 2. The cross-barf is placed as shewn and is pulled
upwards by the cords or chains k k running over the pulleys e e and attached to
the springs E E as shewn. When the space allows the springs can be placed
overhead and act upwards without the intervention of the pulleys e. e.
The spindle D is attached to the disc C by means of a suitable central hook c¹
or equivalent device to allow freedom angularly. The raised position of the
point of attachment secures a tendency on the part of the disc to remain in a
horizontal position.
The antifriction guide rollers g. 9. are applied and act as in the former case.
The object of having the disc C of large size and the diaphragm A of non-
elastic highly flexible material is to maintain as nearly as possible an equal
area of surface for the pressure to act upon at all positions of the disc. The
conical diaphragm of oiled silk has special qualities rendering it most suitable
for the purpose.
It will be understood that any scale of pressures can be adopted the springs
being adjusted accordingly and one of the advantages of a diaphragm as compared
with the syphon vessel as described in my previous Patent above referred to is
that a more extended vertical scale can be used without any multiplying
. mechanism. For example I can obtain four inches of vertical movement for a
variation of only two inches of water column and by suitable strength and

page_text: adjustment of springs I obtain correct proportionate intermediate records. There
are the further advantages of an absence of trouble from freezing and evaporation
and simplicity of construction.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed I declare that what I
claim is
1. In recording apparatus actuated by air or gas pressure, a flexible impervious
diaphragm to receive and transmit the fluctuations of such pressure to the
recording marker substantially as and for the purposes herein before described
and illustrated in the accompanying drawings.
2. The conical flexible nou-elastic diaphragm attached to a large sized disc
substantially as and for the purposes hereinbefore described and illustrated in
the accompanying drawings.
3. The light hollow vertical spindle guided by antifriction rollers and resting
upon or attached to the disc used in conjunction with a diaphragm substantially
as and for the purposes herein before described and illustrated in the accompanying
drawings.
4. The adjustable spiral tension springs operating to depress the spindle and
disc for pressures above the atmosphere and operating to raise them for pressures
below the atmosphere substantially as and for the purposes hereinbefore described
and illustrated in the accompanying drawings.
Dated this 2nd day of February 1894.
EDGAR CONISTON MILLS.