IMPROVE- MENTS IN APPARATUS FOR OBTAINING MOTIVE POWER
Year: 1866

page_text: PROVISIONAL SPECIFICATION left by Geminiano Zanni at the Office
of the Commissioners of Patents, with his Petition,-on the 17th March
1866.
I, GEMINIANO ZANNI, of Rathbone Place, Oxford Street, in the County of
Middlesex, do hereby declare the nature of the said Invention for "IMPROVE-
MENTS IN APPARATUS FOR OBTAINING MOTIVE POWER," to be as follows:-
My improvements in apparatus for obtaining motive power relate, first, to
the application of hydrostatic and pneumatic pressure, for the purpose of pro-
ducing rotary motion to an axis, in combination with the gravitating power of
a.weight or fluid previously raised into such a position above the centre of
gravity of such axis as to give preponderance to one side thereof, and thus
cause it to make half a revolution, and so on in succession, whereby con-
tinuous rotatory motion is imparted to the central axis, from which the power
obtained may be-transmitted by toothed wheels or other suitable mechanism.
One arrangement of mechanism or apparatus which I employ in carrying
out the first part of my Invention consists of an air-tight drum or cylinder,
formed in two parts, mounted upon an axis, and arranged to revolve together
with the axis as one drum or cylinder. The two parts are so formed that
when two of their sectional surfaces on one side of the axis meet or come
together an angular recess (radiating from the axis to the periphery) is left
between the two parts on one side of the drum, thus causing the drum for the
time to be lighter on that side than the other. The two parts of the drum
are capable of movement upon the axis, the angular recess being alternately

page_text: sformed on opposite sides of the axis, the closing of the parts together on one
side thus causing the angular recess or opening to be formed on the opposite
side. The central axis is supported in suitable bearings in a tank of water or
other liquid, one end of the axis passing through a stuffing box on the side of
the tank. When the tank is partly filled with water, so as nearly to submerge
the drum, the buoyancy of the air-tight sections of the drum will cause them
to close together at the upper part, and thus raise the central weighted parts
of each section above 'the centre of gravity of the central axis. The buoyant
action of the parts also causes a column of mercury or other fluid. (or it may
be a weight) to be forced to the upper circumference of the drum, so as to
give it a preponderance in the direction in which it is intended to rotate. In
this position the parts are retained together for a time by a spring or other
suitable catch, the angular recess between the two parts being on the under
side of the drum. The drum in this position having a preponderance of
weight on the upper side has a tendency to make a partial revolution by
giving it a slight impetus in one.or the other direction. When the heavy side.
of the drum has nearly reached the centre of gravity on, the descending side
the spring catch is released by self-acting mechanism, the buoyancy of the
parts causing them to separate on the under side, at the same time closing the
angular recess on the upper side of the axis, thus again giving preponderence
to the upper side of the rotating drum formed by the sectional air chambers.
The centrifugal force acquired by the parts when once set in motion causes.
them to continue their rotation in the same direction, the opening and closing
of the parts in succession causing the repeated transferrence of the weight to
the upper side of the drum. The rotary motion thus imparted to the central
axis may be transmitted by suitable mechanism for driving machinery, or
for the application of the power for the purpose for which power may be
required.
According to the second part of my improvements, in place of submerging
the apparatus, as previously described, the divided drum or sectional wheel
may be caused to rotate in the air. The closing of the angular recess on the
Jower circumference by the gravitation of the parts in opposite directions
causes a column of mercury or other fluid (supported by arms on the rotating
axis) to be forced by the gravitating pressure from a chamber opposite or near
the lower circumference into a chamber opposite the upper circumference of
the drum, thus giving a preponderance of weight to the upper side or cir-
cumference of the rotating parts after each semi-rotation; or this pre-
ponderence may be given to the upper descending side of the drum or
wheel by 'means of pneumatic bellows placed between the opening and

page_text: closing parts, and actuated by their gravitation to raise or force a weight,
quicksilver, or liquid to the outer circumference on the upper descending side
of the rotating parts; or a rack and pinion or other mechanism may be
actuated by the gravitating power of the sectional parts of the wheel to raise
a weight into a position above the centre of gravity, so as to give pre-
ponderence to the upper circumference of the rotating parts. It is not
essential, according to this part of my Invention, that the parts mounted on
the rotating axis should be in the form of a drum or wheel, as lever arms
mounted on the axis may be actuated and caused to rotate by similar means.