IMPROVEMENTS IN OBTAIN- ING MOTIVE-POWER FROM THE VARYING PRESSURE AND TEMPERATURE OF THE ATMOSPHERE
Year: 1876

page_text: PROVISIONAL SPECIFICATION left by Joseph Durham Erskine Huddart at
the Office of the Commissioners of Patents on the 23rd February 1876.
JOSEPH DURHAM ERSKINE HUDDART, of Anerley. "IMPROVEMENTS IN OBTAIN-
ING MOTIVE-POWER FROM THE VARYING PRESSURE AND TEMPERATURE OF THE
ATMOSPHERE."
This Invention has for its object the lifting of various kinds of weights, chiefly
those of clockwork and other similar machinery, by means of atmospheric pressure
and heat which I propose to utilise by availing myself of any variation however
I
slight either in the pressure or temperature of the atmosphere. For this purpose
construct an air cylinder of any suitable shape, or instead thereof I may use a
column of mercury or a vacuum chamber and on one side thereof in a suitable
position I provide a piston rod or other suitable contrivance working in any suit-
able manner, which rod I connect to an endless band passing over any suitable
pulleys; such pulleys are connected to a ratchet wheel fixed in suitable bearings,
which wheel gears into ratchet teeth formed on the upper end of a second piston and
rod; this second piston and rod is the main governor or motor of the machine and
its base is attached to a piston placed at the top of the air cylinder first described.
When the pressure of the atmosphere is at a maximum, say 15lbs. to the square
inch, the main piston is depressed to the lowest point, but upon the slighest variation
the spindle revolves, and thereby raises any fluid such as mercury or water to a
reservoir provided for its reception. By this means I accumulate a store of motive
power which I am enabled to use continuously or otherwise as occasion may require,
and in order to obviate the disadvantages arising from the intermittent nature of
the motive power thus obtained I propose to preceed as follows:-I provide a
suitable helical tube having a spindle passing through its centre, such spindle being
inclined at a suitable angle and connected with the ratchet wheel attached to the
main piston, and upon the slightest variation of such piston the air contained in
the interior of the air cylinder expands and thus imparts motion to the ratchet
wheel, which then works the truncated pulleys to which the weights required to be
lifted are attached, when such weights are at once caused to rise.
In order to counteract the tendency of the air piston to rise at every slight pres-
sure and to control its action until the maximum atmospheric pressure is obtained
I provide a case similar to that of an aneroid barometer and to its upper
surface I attach a rod jointed to a metal brace having a suitable slot therein to
377

page_text: permit of pin a taking into it; such pin is fixed to a metal arm which is attached
by means of a pivot to a suitable bearing, the lower end of which arm gears into
the teeth of a cog wheel which is fixed on the same axle as the ratchet wheel
before described. By this means the piston is arrested in its motion until the
atmospheric pressure has attained its minimum and is about to increase, thus
avoiding any unnecessary and useless expenditure of the motive power before
described.
The amount of motive power to be obtained from the atmospheric pressure may
at any time be easily approximately ascertained from an ordinary barometer chart.
In order to ensure the ratchet teeth formed on the top of the main piston rod
gearing with the ratchet wheel when such piston rod ascends to the requisite
height I provide a roller fixed in suitable bearings and which is pressed forward by
any suitable spring against the main piston rod and so keeps it in position.