Improvements in Paddle Wheels or the like.
Year: 1897

page_text: Date of Application, 18th Dec., 1897
Complete Specification Left, 19th Sept., 1898-Accepted, 5th Nov., 1898
PROVISIONAL SPECIFICATION.
Improvements in Paddle Wheels or the like.
A
I, CHARLES GRAYSON, of 29, Ullet Road, Liverpool, in the County of Lancaster,
Ship Builder, do hereby declare the nature of this invention to be as follows:-
My invention has for its object an improved construction of paddle wheels.
paddle wheel made in accordance with my invention differs from those ordinarily in
use inasmuch as the blades or floats are arranged in pairs at an angle with the wheel
axis instead of parallel thereto.
Each blade is shaped somewhat after the contour of the blades of a screw
propeller and may be Hat or suitably curved. They are supported on a central boss
lying normally a little distance above the water level. There may be any desired
number of blades but I prefer eight on each wheel arranged in pairs so as to form
four radial double propelling members. The apex of the angle formed by the
meeting of each pair preferably the forward edge, and a small space may be
left between them to allow a portion of the water to flow through and thus reduce
the shock of impact. The blades are preferably of metal plate and in some cases
are hollowed for lightness, and stayed with tie rods or angle irons for strength.
The two bosses of the paddle wheels are mounted on a shaft or shafts and con-
nected with the source of motive power in such manner that they may revolve
independently or in opposite directions.
If preferred my paddle wheels may be placed near the stern of the vessel and
connected with the engines by bevel or other gearing.
They may also be provided with feathering mechanism.
I contemplate driving my wheels at a speed considerably greater than is usual
with paddle wheels.
Dated thin 17th duer of Danambar 1807
CHARLES COVENTRY,
Patent Expert, Agent for the Applicant.
I, CHARLES GRAYSON, of 29, Ullet Road, Liverpool, in the County of Lancaster,
0 Ship Builder, 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 invention has for its object an improved construction of paddle wheels. A
paddle wheel made in accordance with my invention differs from those ordinarily

page_text: 1
in use inasmuch as the blades or floats are arranged in pairs at an angle with the
wheel axis instead of parallel thereto. Each blade is shaped somewhat after the
blades of a screw propeller and may be flat or suitably curved. They are supported
on a central boss lying normally a little distance above the water level. There
may be any desired number of blades but I prefer six or eight on each wheel
arranged in pairs so as to form three or four double propelling members respectively.
I do not confine myself to any particular number of blades.
In the drawing Fig. 1 is a side elevation of a propeller constructed according to
my invention and having three pairs of blades.
Fig. 2 is a plan.
In my Provisional Specification I stated that I preferred to so arrange the blades
that the apex of the angle formed by each pair should be the forward edge, but
I find in practice that a better grip of the water is obtained by reversing this
position, and I therefore show the latter arrangement.
A shows the shaft and B the boss. Arranged symmetrically round boss B and
rigid therewith are the blades C. The arrows in Fig. 1 show the direction preferred
-for going ahead, the reverse motion being employed for astern.
Each blade is formed on the lines of a true oval or ellipse but is hollowed or cut
away at a, thus forming a nose b, and it is intended that said nose shall be the
first portion to strike the water. The rear edge of each blade is also of a somewhat
flatter curve than the true oval and this is of importance in that it minimises the
lift of water as it leaves the surface.
The blades of each pair are fitted at a slight angle with each other (see Fig. 2)
and as they enter the water their tendency is to grip or compress some of the water
between them, thus securing a good hold thereon. A space is left between the
adjacent edges of each pair of blades to allow them to leave the water cleanly, and
I have found in actual practice that a remarkably good propelling effect, as well as
great freedom from lifting water is shown.
The best results are given by driving the shafts at a speed considerably greater
than ordinary paddle wheels, say from 60 to 100 revolutions per minute, the speed
preferably being raised as the forward movement of the vessel increases with the
object of preventing undue churning of the still water.
The blades may be of sheet metal, and in some cases especially when of large
size may be hollowed for lightness, and stayed with tie rods or
angle irons.
I have so far explained my propelling devices as applied amidships as is the case
with ordinary paddles, but I do not confine their application to that situation as
they may be for instance mounted on a stern shaft such as is used for navigating
shallow water or rivers.
Having now particularly described and ascertained the nature of my said
invention and what manner the same is to be performed, I declare that what
I claim is:-
1. A propelling device comprising a central boss carrying a number of pairs of
blades, those of each pair being arranged at an angle with each other with a
through space between them, and each of said blades being hollowed or cut away as
at a so as to form a nose b, substantially as described.
2. In a paddle wheel a sèries of blades approximately oval, but cut away as at a,
and having noses b, substantially as described and shown.
Dated this 17th day of September 1898
CHAS.
COVENTRY.
Patent Expert, Agent for the Applicant.