Improvements in Screw Propellers.
Year: 1899

page_text: · Date of Application, 18th Oct., 1899
Complete Specification Left. 5th July, 1900-Accepted, 11th Aug., 1900
Improvements in Screw Propellers.
I, EDMUND EDWARDS, of the Firm of Edwards and Co., Chartered Patent
Agents and Engineers, of 65 and 66, Chancery Lane, in the County of Middlesex,
do hereby declare the nature of this invention to be as follows:-
This invention relates to a screw propeller distinguishable from the propellers
ordinarily used by having helical blades, the threads of which are of greater
pitch towards the back of the propeller than in front.
The advantage of this arrangement is that the screw-threads of the back part
are able to effect a useful pressure upon the water (which has itself been set in
movement in a longitudinal direction backward by the threads of the front part
of the propeller), and this pressure accelerates the ship's propulsion.
By this thorough utilization of the inertia of the water, as distinguished from
other propelling arrangements ordinarily used, a reduction of the diameter of
the screw is made possible, an arrangement of great value on canal boats or
vessels built or coupled together.
In the latter case the driving of the helical propeller may be effected in
different ways, for instance, by means of treadles of a kind similar to those
ordinarily used on bicycles.
Through the chain-wheels which are brought into motion by the treadle-cranks,
the power is transmitted to a pair of bevilled wheels, from thence to an inter-
mediate shaft, and from this shaft by means of chains to the shaft of the helical
propeller.
The steering of the boat is done in the usual way; one of the handles of the
treadle-frame being arranged for the purpose, so that its movement can be trans-
mitted to the axis of the rudder by suitable means.
The improved screw-propeller may be applied not only to vessels, but in larger
dimensions to air-ships.

page_text: !
A communication to me from FRANZ OTTO NEUHÄUSER, of Zwickau, Bohemia,
in the Empire of Austria, Baker.
I, EDMUND EDWARDS; of the Firm of Edwards and Co. Patent
Agents and Engineers, of 65 and 66, Chancery Lane, in the County of Middlesex,
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 follow-
ing,statement,, and accompanying drawing that is to say:-
:-
This invention relates to a screw propeller distinguishable from the propellers
ordinarily used by having a helical blade, the pitch of which is greater towards
the back end of the propeller than in front.
The advantage of this arrangement is that the screw blade of the back part is
able to effect a useful pressure upon the water (which has itself been set in
movement in a longitudinal direction backward by the blade of the front part
of the propeller), and this pressure accelerates the ship's propulsion.
By this more complete utilization of the inertia of the water, as distinguished
from other propelling arrangements ordinarily used, a reduction of the diameter
of the screw is made possible, an arrangement of great value on canal boats, or
vessels built or coupled together.
In the accompanying drawing, which is in illustration of the invention,
the improved screw-propeller is shown arranged between two boats connected
together.
Figure 1 is a side view of the propeller, one of the boats being removed, and
showing driving gear of the ordinary known kind.
Figure 2 is a plan, the driving gear not being shown.
As is shown in the drawing, the pitch of the blade of the propelling screw a
increases from the front to the back, so that the water, which by the revolution of
the screw is driven backward by the forward part of the blade of the screw,
attains on account of the increase of the pitch and consequent greater inclina-
tion of the blade at the back end-a further acceleration, the back of the blade
continuing to experience a propelling effect against it.
The driving of the propeller may be effected in any convenient way. For
instance (as illustrated in Figure 1) it may be done in the well-known way
by means of pedals, similar to those ordinarily used on bicycles.
Through the chain-wheels c, which are rotated by the pedal cranks, the
power is transmitted by means of the bevilled toothed wheels d, e, to the shaft f,
and from the latter by means of chain gear to the screw-shaft h.
The steering of the boat is also effected in the usual well-known way, one of
the handles of the treadle frame (in the figure the centre one) being arranged
for the purpose. It actuates the spindle and, by means of the bevilled toothed
wheels, m, turns the shaft n which, by means of bevilled wheels o, ?, drives a
spindle and chain wheels and chain s, actuating the rudder t..
The improved screw propeller may be applied not only to boats, but also, by
largely increasing the dimensions to the propulsion of airships.
Having now particularly described and ascertained the nature of the said
invention, and in what manner the same is to be performed, I declare that what
I claim is:
A screw-propeller, the blade of which increases in pitch from the front to

page_text: the back or rear end, whilst remaining of the same diameter, so that pressure may
be effected upon the water which has been brought by the blades of the front
part of the propeller in accelerated movement to the blades at the rear part of the
propeller, substantially as described and illustrated.
T] th 1 of TL 1000
EDWARDS & Co.,
Chartered Patent Agents, 65 and 66, Chancery Lane, London,
Agents for the Applicant.