Improvement in Propeller Shafts.
Year: 1895

page_text: Date of Applicati n, 11th Nov., 1895
Complete Specification Left, 10th Dec., 1835-Accepted, 11th Jan., 1856
PROVISIONAL SPECIFICATION.
Improvement in Propeller Shafts.
WO WILLIAM MENZIES of 50 Side Newcastle-on-Tyne, Engineer and JAMES
STENHOUSE of 50 Side Newcastle-on-Tyne Engineer do hereby declare the nature
of this invention to be as follows:-
Our invention relates to the prevention of corrosion which takes place upon
propeller shafts between the brass liners by means of the following method:-
Two hoops are shrunk on to the propeller shaft between the brass liners and are
so placed that the edges next to the brass liners are kept about two inches away
therefrom.
:
The space thus formed is filled up with india rubber ring or rings or other
suitable packing so as to ensure a tight fit between the end of the brass liuor on
the one side and of the hoop on the other thus forming a water tight joint in each
case.
The inside ends of the hoops are bevelled down to facilitate removal 'and
replacement of shaft.
The accompanying drawing is explanatory of our invention & referring thereto
Sis the propeller shaft, B are the brass liners, H are the hoops and P the space
for the packing.
Dated this 17th day of December 1895.
;
A. CRAWHALL CHAPMAN,
Agent for Amending the Provisional Specification filed by the Inventors.
COMPLETE SPECIFICATION.
Improvement in Propeller Shafts.
We, WILLIAM MENZIES and JAMES STENHOUSE both Engineers of 50 Side
in the City and County of Newcastle-on-Tyne, 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 an improvement in propeller shafts and has for its object
the prevention of the corrosion which takes place between the brass liners and
the body of steel or iron propeller shafts in contact with salt water.
Hitherto it has been customary to wrap packing round the shaft at the junction
of the end of the brass liner with the shaft for the purpose of preventing access
of water at the points where the two different metals meet but this method has
been found ineffectual owing to there being no means of keeping the packing tight
or in its position against the ends of the liners but by our invention we shrink or
otherwise suitably secure or form on the shaft hoops of wrought iron or steel (or
other metal that in the presence of salt water will not set up corrosion between
itself and the shaft) at a distance from the liners of about two inches and in the
space between the ends of the hoops and the ends of the liners we insert the

page_text: packing which is thus prevented from slipping along the shaft or working loose
and so maintains a perfectly watertight joint between the different metals. The
packing may consist in each case of an india rubber or other equivalent ring or
rings sprung over or lapped in the usual manner round the shaft.
We will more fully describe our invention with reference to the accompanying
drawing which shows partly in elevation and partly in section a propeller shaft in
which is the coupling flange and 2 are the brass liners hereinabove alluded to,
3 representing the boss of the propeller. 44 are wrought iron or steel hoops as
above described shown secured in position a little distance from the ends of the
liners and 5 is the packing shown making a watertight joint between the ends of
the liners and the body of the iron or steel shaft 6.
In practice we keep the diameter of the rings 4 slightly less than the diameter
of the liners and in fitting the packing we keep its upper surface slightly below the
level of the rings or hoops and the inside ends 7 of the hoops or rings 4 may if desired
be bevelled down as shown to facilitate removal and replacement of the shaft.
In the drawing we have shown two different types of packing secured in the
manner described and it will be observed that the rings 4 act as thrust pieces
against which we secure the packing and these thrust pieces also act very effectually
in protecting the packing from injury or displacement while shipping the shaft into
the stern tube.
Having now particularly described and ascertained the nature of our said inven-
tion and in what manner the same is to be performed we declare that what we
claim is :-
Forming on propeller shafts opposite the ends of the brass liners raised surfaces
or rings or hoops between or against which and the ends of the brass liners packing
is secured the rings acting as thrust-pieces to pack against for the purposes of
forming a watertight joint between the ends of the liners and the shafts and also
as protecting rings to the packing substantially as herein set forth.
Dated this 9th day of December 1895.
A. CRAWHALL CHAPMAN,
3 St. Nicholas Buildings, Newcastle-on-Tyne, Patent Agent.