Improvements in Gas-pressure Gauges.
Year: 1890

page_text: Date of Application, 6th Jan., 1890
Complete Specification Left, 4th Oct., 1890-Accepted, 8th Nov., 1890
PROVISIONAL SPECIFICATION.
Improvements in Gas-pressure Gauges.
I, THOMAS THORP of Whitefield in the County of Lancaster Engineer do hereby
declare the nature of this invention to be as follows:-
The object of this invention is to obviate the use of water or other liquid for the
purpose of ascertaining the pressure of gas in the mains or other reservoirs.
Up to the present time no method of accomplishing this object in a sufficiently
accurate manner has been in vogue as the joints links and other means usually adopted
to give the requisite amplification have proved fatal to the obtaining of accurate
readings.
In the pressure gauge constructed according to my invention I make use of thin
metallic discs preferably corrugated in a concentric manner. These discs are attached
in couples at their peripheries, and at their centres, leaving a communication between
them, to the centres of other similarly coupled discs, one free end of the series being
attached to the gas supply, thus forming a kind of bellows which become extended or
contracted according to the pressure exerted from within or without but only having
a very slight amount of motion as compared with the amplification required.
To effect this amplification without perceptible friction I make use of one more of
these bellows and by preference, two, attached to the opposite sides of a ring and
both being in communication with the gas supply; the inner ends of the bellows will
thus be opposite to each other and are furnished with projections extending some
distance past each other, but not in contact.
To these projections I attach very thin metal strips passing round and secured to a
central roller or axle in such a manner that. as the bellows approach or recede from
each other, the axle is rotated by the winding and unwinding of the thin metal strips
and no perceptible friction is experienced.
The ring to which the bellows are attached is preferably fitted inside a metallic box
or case, the gas pipe protruding through one side of it. On the opposite side I fit a
screw preferably having a milled head, and extending into the inside of the case as
far as the ring which being somewhat flexible yields to the pressure of the screw and
thus causes the bellows to approach or recede from each other, the object of this
screw being to enable the pointer to be adjusted to zero without the usual
troublesome plan of taking the instrument in pieces which is adopted under similar
circumstances.
A properly graduated dial through which one end of the axle passes, and a
pointer secured to the end of the axle, with the usual glass and bezel complete
the whole, which may be fixed in any desired position without affecting its
efficiency.
It will of course be readily seen that instead of the usual dial and pointer, or
in addition thereto, a lengthened lever carrying a marking pen or pencil may be
used to indicate and record upon a suitable surface a continuous diagram of the
pressure.
Dated this 4th day of January 1890.

page_text: COMPLETE SPECIFICATION.
Improvements in Gas-pressure Gauges.
I, THOMAS THORP of Whitefield 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 :-
.
The object of this invention is to obviate the use of water or other liquid for the
purpose of ascertaining the pressure of gas in the mains or other reservoirs.
In the pressure gauge constructed according to my invention I make use of thin
metallic discs, preferably corrugated in a concentric manner. These discs are attached
in couples at their peripheries and at their centres leaving a communication between
them, to the centres of other similarly coupled discs, one free end of the series being
attached to the gas supply thus forming a kind of bellows which become extended or
contracted according to the pressure exerted from within or without, but only having a
very slight amount of motion as compared with the amplification required.
To effect this amplification without perceptible friction I make use of one or more
of these bellows and attach them to the inner and opposite sides of a ring, both sets of
bellows being in communication with the gas supply. The inner ends of the bellows
are thus opposite each other & are furnished with projections of a suitable shape
extending some distance past each other but not in contact.
To these projections I attach very thin metal strips passing round & secured to a
central roller or axle in such a manner that as the bellows approach each other or
recede therefrom, the axle is rotated by the winding & unwinding of the thin metal
strips & no perceptible friction is experienced.
The ring to which the bellows are attached is preferably fitted inside a metallic box
or case, the gas pipe protruding through one side of it. On the opposite side I fit a
screw having preferably a milled head and extending into the inside of the case as far
as the ring, which by reason of its thinness is somewhat flexible & yields to the
pressure of the screw, thus causing the bellows to approach or recede from each other,
the object of this screw being to enable the pointer to be adjusted without the trouble
of taking the instrument in pieces.
A properly graduated dial, through which one end of the axle passes & a pointer
secured to the end of the axle with the usual glass & bezel complete the whole in one
form of the apparatus.
Instead of there being two sets of bellows, one set only may be used, the
projection to which the thin metallic strips are attached being fixed to the opposite
side of the ring.
It will of course be readily seen that instead of the usual dial and pointer or
in addition thereto, a lengthened lever carrying a marking pen or pencil may
be used to indicate and record upon a suitable surface a continuous diagram of the
pressure.
And in order that my invention may be fully understood and readily carried into
effect I will proceed to describe the accompanying sheet of drawings, reference being
had to the figures and letters thereon marked similar letters referring to similar parts
throughout the several views.
Fig. 1, is a front elevation, with portion of glass, bezel & dial removed, of one form
of pressure gauge constructed according to my invention.
Fig. 2, is a sectional elevation of the same through A. A.
Fig. 8, is a front elevation, with portion of glass, bezel & dial removed, of another
form of pressure gauge constructed according to my invention, and
Fig. 4, is a sectional elevation of the same through B. B.
In Figs. 1, 2, 3, 4, a, a, are the metallic bellows formed of thin corrugated metal
plates in communication with the gas supply pipe b. b. c is the ring to which the
pipe 66 of the bellows a. a is attached. d,d, are the projecting pieces with which the

page_text: bellows are furnished and having the thin metallic strips e, e, attached; these strips
also pass partially round the axle f and are secured to it.
9, is the metallic box or case in which the ring c is fitted, h is the milled head screw
passing through the case g & pressing upon the ring c. i is the graduated dial (which
may be of any convenient diameter) through which one end of the axle f which
carries the pointer K passes.
Having now particularly described & ascertained the nature of my said inven-
tion & in what manner the same is to be performed I declare that what I
claim is :-
1. In gas pressure gauges, the use of bellows a, formed of thin metallic discs
attached to & in communication with the gas supply pipe, fitted to either one or both
sides of a ring & having projections d furnished with thin metallic strips e passing
partially round and secured to an axle carrying a lever or pointer separately and in
combination, substantially as herein described & shown on the accompanying sheet of
drawings.
2. In gas pressure gauges, the combination of the ring c & screw h substantially
as shown on the accompanying sheet of drawings & herein described.
3. In gas pressure gauges, the combination of one or more sets of bellows attached
to and in communication with the gas supply pipe & having projections furnished with
thin metallic strips passing partially round & secured to an axle carrying a lever
holding a pen or pencil or their equivalent for the purpose of continuously recording
the gas pressure upon a suitable surface, such as a driven drum.
Dated this 3rd day of October 1890.
THOMAS THORP,
Applicant.