Improvements relating to the Propulsion of Light-draught Vessels.
Year: 1899

page_text: Date of Application, 26th Oct., 1899-Accepted, 23rd Dec., 1899
COMPLETE SPECIFICATION.
Improvements relating to the Propulsion of Light-draught Vessels.
I, WILLIAM VANCE, of Prescott, County of Greenville, Province of Ontario,
Canada, Railroad Employee 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:-
-
This invention relates to improvements in vessels propelled by screw propellers,
and its object is to provide a vessel which is especially adapted for service in
shallow water. A further object is to provide a light draught vessel with an
improved screw propeller. A further object is to provide a light draught vessel
driven by a screw propeller, which simple in construction, efficient and powerful
in operation and which can be manufactured at a moderate cost.
To these ends, the invention consists in a light draught vessel, actuated by
a screw propeller, constructed substantially as herein illustrated and described
and defined in the appended claims.
Referring to the drawings, in which similar letters of reference indicate similar
parts.
Figure 1 is a view in elevation of a vessel constructed in accordance with this
invention.
Figure 2 is a stern view thereof.
Figure 3 is a bottom view of a modified form.
Figures 4 and 5 are details, showing the construction of one form of propeller
employed with the improved vessel.
Figures 6 and 7 are modified forms of screw propellers.
In the drawings, (A) represents a vessel of any usual or preferred type, but
having a comparatively broad beam and of little depth, so as to adapt it for
use in shallow water. The body-portion of the vessel is cut away at the rear,
forming an open space which extends from a point approximately the middle
throughout the remainder of the length of the boat. By this construction a
very short keel (a) is formed, the remainder of the hull behind the keel (a) being
very shallow and comparatively flat bottomed.
From the termination of the keel (a), the keel extension (a¹) may be extended
rearwardly at the stem (a²), to which it is securely connected. The stern
post (2) is suitably braced by the side bars (a³), as clearly shown in Figure 2.
The propeller shaft (B) is journalled in suitable bearings formed in the
keel (a) and the stern post (a²), and is provided with propeller blades (6), of which
there are preferably two, which are spirally wound upon said shaft (B) and so
constructed that every point of the periphery of said blades is substantially
perpendicular to the axis of said shaft. As shown, the propeller blades extend
substantially two convolutions and a half, but it is evident that they may be of
greater length, thus ensuring great power and effectiveness.
Any suitable motive power may be connected to the said propeller shaft for
driving the same,
It is obvious that instead of extending the keel extension from the end of the
keel (a) to the stern post (a²), a separate rod may be substituted therefor, which

page_text: may be secured in place in any suitable manner, this change being so simple
and obvious as to necessitate no detailed illustration.
In the form shown in Figure 3, the construction is in all respects similar to
that shown in Figure 1, excepting that instead of extending the keel extension
back to the stern post, the keel itself is so extended, forming a dividing plate (D).
Upon the end of the plate (D) is fixed a cross bar (), which may be suitably
braced, the ends of this cross bar forming bearings in which the ends of the
propeller shafts (B¹) are journalled. The forward ends of the shafts (B), are
journalled upon either side of the keel (a), and are connected to a suitable
driving power carried by the vessel, as will be readily understood.
It is obvious that the plate (D) instead of forming an integral portion of the
keel may be separate and secured in place.
By means of the keel extension and the plate (D), the propeller screws are
protected from injury.
The blades (6) of the propeller are preferably constructed as shown in Figures 4
and 5, being formed in separate parts, having horizontally extending flanges (61)
which are adapted to be riveted to the shaft (B).
The spiral upon which the propeller blades are wound may vary in curvature
as desired, two extreme forms being shown in Figures 6 and 7.
While I have herein shown a preferred form of carrying my invention into
effect, yet I do not desire to limit myself to such preferred details of construction,
but claim the right to use any and all modifications thereof which will serve to
carry into effect the objects to be attained by this invention in so far as such
modifications and changes may fall within the spirit and scope of my said
invention.
Having now particularly described and ascertained the nature of my said
invention, and in what manner the same is to be performed, declare that what
I claim is :-
1. A vessel provided with a screw propeller, constructed and arranged sub-
stantially as herein described and shown.
2. A vessel having a shallow keel terminating at a point forward of the centre
of the vessel; and a screw propeller extending from the keel to the stern post
and journalled in bearings formed therein, substantially as described.
3. A vessel having, a shallow keel terminating at a point forward of the centre
of the vessel; a screw propeller extending from the keel to the stern post and
journalled in bearings formed therein; and a protecting bar secured to said keel
and stern post and extending beneath the said screw propeller, substantially as
described.
4. A vessel having a shallow keel terminating at a point forward of the centre
of the vessel; a screw propeller arranged on each side of said keel and extending
thereform to the stern post, and journalled in suitable bearings carried by said
keel and stern post, substantially as described.
4. A screw propeller for light draught vessels, comprising a shaft; propeller
blades adapted to be secured to said shaft, each of said propeller blades being
formed separately and having flanges and a central blade which is perpendicular
at every point to the axis of the shaft, substantially as described.
Dated this 26th day of October 1899.
BOULT, WADE & KILBURN,
Agents for the Applicant.