Improvements in Steam Engine Indicators.
Year: 1898

page_text: PROVISIONAL SPECIFICATION.
Improvements in Steam Engine Indicators.
I, JOHN CLARK DOBBIE, of 45,. Clyde Place, in the City of Glasgow, Nautical
Instrument Maker, do hereby declare the nature of this invention to be as
follows
14.
This invention which relates to steam engine indicators of the Richard's type
.or of other kinds has for its object to provide means whereby the length between
centres of the indicator arm or of the radius bars, levers or links of such indi-
cators may be accurately adjusted and set.
For that purpose the arms, bars, links or levers of the indicator are each
formed of a tube or partly tubular and partly solid, and the forked or other
eyes by which they are jointed together have their shanks screw threaded and
fitted into the ends of the tubes which are internally screw threaded to receive
said shanks. The screw threads at one end of each tube are right handed and
those at the opposite end left handed, and by slight turning movement of the
tube on the end eye shanks the centres of the eyes may be made to approach or
recede from each other to a very minute extent so that accurate adjustment is
allowed for. When the required adjustment has been effected the tubes and
shanks are pinned together or are prevented from turning on each other by
soldering or by like means.
Dated this 12th day of Var 1808
WALLACE FAIRWEATHER,
Of the Firm of Cruikshank and Fairweather,
Chartered Patent Agents,
Saint Vincent Street, Glasgow, Agent for the Applicant.
Improvements in Steam Engine Indicators.
I, JOHN CLARK DOBBIE, of 45, Clyde Place, in the City of Glasgow, Nautical
Instrument Maker, do hereby declare the nature of this invention and in what
manner the same is to be performed, to be particularly described and ascer-
tained in and by the following statement:-
-
This invention which relates to steam engine indicators of the Richard's type
or of other kinds has for its object to provide means whereby the length between
centres of the indicator arm or of the radius bars, levers or links of such indi-
cators may be accurately adjusted and set.
The accompanying drawing shews the invention applied to the parallel motion
of a Richard's or like indicator.

page_text: The arm A, and bars, links or levērs B of the indicator are each formed of a
tube or partly tubular and partly solid, and the forked or other eyes A¹ by which
they are jointed together have their shanks A2, 132, screw threaded and fitted
into the ends of their respective tubes which are internally screw threaded to
receive said shanks. The screw threads at one end of each tube are right handed
and those at the opposite end left handed, as shewn, and by slight turning move-
ment of the tubes A, B, on the end eye shanks A3, B2, the centres of the eyes
may be made to approach or recede from each other to a very minute extent so
that accurate adjustment is allowed for. When the required adjustment has
been effected the tubes and shanks are pinned together or are prevented from
turning on each other by soldering or like means.
Having now particularly described and ascertained the nature of my said in-
vention, and in what manner the same is to be performed, I declare that what
I claim is;-
A steam engine indicator having its arm, radius bars, levers or links made
up of internally screw threaded tubes secured upon screw threaded shanks formed
on the joint parts substantially as and for the purpose set forth.
1
T
101
1
73
1000
WALLACE FAIRWEATHER,
Of the Firm of Cruikshank and Fairweather,
Chartered Patent Agents,
62, Saint Vincent Street, Glasgow, Agent for the Applicant.