An Improved Apparatus for Propelling Ships, Boats, and other Craft.
Year: 1896

page_text: Date of Application, 3rd Jan., 1896-Accepted, 8th Feb., 1896
COMPLETE SPECIFICATION.
An Improved Apparatus for Propelling Ships, Boats, and other
Craft.
I, JOHANN BAPTIST HIRSCHMANN of 9 Schwaltbacherstrasse, Eltville, Germany,
Merchant, 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:-
Screw propellers as hitherto used for ships have the defect, that, whilst the
water acts fully on the outermost parts of the blades the parts near the rotating
shaft produce little or no power. Moreover with the screw propellers generally
used it is impossible to speedily turn the ship or to move it in a lateral direction.
My invention has for its object, by means of an improved propelling apparatus,
to overcome the aforesaid objections.
My improved screw propeller has the advantage of imparting to the vessel, with
but a small expenditure of power, a greater speed than could be obtained with
ordinary screw propellers.
One screw can be arranged at each side of the ship and also, if necessary, one
below the keel. I prefer however to use two screws one located at each side of the
keel. Under my invention the propeller is made of a spirally twisted vane or
blade and the longitudinal shaft as now used is dispensed with so that the full power
of the water is utilized.
The number of convolutions of the screw will be proportionate to the space
available and the tonnage of the vessel, while the speed will depend upon the pitch
of the convolutions.
The improved screw can be driven direct from the piston of an engine or by
means of toothed gearing, or by chains and sprocket wheels.
And in order that my invention may be properly understood I have hereunto
appended by way of example an explanatory sheet of drawings.
Fig. 1. is a side view of the propeller.
Fig. 2. is a front view of the same with its driving gear.
Fig. 3. shows another form of driving gear.
Fig. 4. shows a modified form of the screw.
As shown in Figs. 1 and 2, a, a¹, are brackets fixed to the ship's hull and
carrying the bearings b, b', in which the shaft c, c', revolves. This shaft which
carries the screws, extends beyond the bearing b', where it is provided with a small
sprocket wheel d connected by the chain e with a large sprocket wheel mounted
on a suitable shaft and actuated by the connecting rod g of the engine h.
In the arrangement shown at Fig. 3 one end of the shaft c carries a small bevel
wheel which is driven by the large bevel wheel carried on the end of the
projecting shaft W, supported by the bearing 6 and driven direct from the
engine.
The form of propeller shown in Fig. 4 is suitable for ships of small tonnage and
which are required to run at high speeds.
When two of the screws are used, one at each side of a ship, and are revolved
in different directions the ship can be very quickly turned.
If desired the screws, in the case of small craft, can be revolved by hand.

page_text: Having now particularly described and ascertained the nature of my said inven-
tion, and in what manner the same is to be performed, I declare that what I
consider novel and desire to claim is :-
1. An apparatus for propelling ships, boats, and other craft, consisting of one
or more twisted blades or vanes (such as s) arranged at suitable parts of the
vessel and revolved by suitable machinery, substantially as hereinbefore described
with reference to the drawings annexed.
2. The driving gear for the screws consisting of the chain or bevel gearing
arranged outside the vessel and driven direct from an engine or by hand substan-
tially as herein before described and shown.
Dated this 31st day of December 1895.
H. D. FITZPATRICK,
70 Wellington Street, Glasgow, Agent.