IMPROVEMENTS CONNECTED WITH SCREW PROPELLERS FOR STEAM SHIPS
Year: 1879

page_text: LETTERS PATENT to Charles Jones, of the Firm of John Jones and Sons, of
Liverpool, in the County of Lancaster, Engineers, for the Invention of
"IMPROVEMENTS CONNECTED WITH SCREW PROPELLERS FOR STEAM SHIPS."
Sealed the 20th April 1880, and dated the 27th October 1879.
PROVISIONAL SPECIFICATION left by the said Charles Jones at the Office
of the Commissioners of Patents on the 27th October 1879.
CHARLES JONES, of the Firm of John Jones and Sons, of Liverpool, in the County
of Lancaster, Engineers. "IMPROVEMENTS CONNECTED WITH SCREW PROPELLERS
FOR STEAM SHIPS.".
The main objects of the said Invention are to provide means whereby screw
propellers may be more securely connected to their shafts, and also whereby they
maybe more easily unshipped and shipped when necessary.
Under the first part of my Invention I ensure that screw propellers shall be
truly secured to their shafts so as to prevent breakage or other inconvenience
attending the bad fitting which is sometimes the result of the present methods of
attaching propellers on their shafts by forming the end of the screw shaft cylin-
drical, or nearly so, and providing a collar or shoulder at the requisite distance from
I bore out the
the end to receive the thrust of the propeller when screwed up.
boss of the propeller conically from one or both ends, and secure it in position on
the shaft by means of one or two coned clips, preferably split, and provided with a
key or keys. The said cone or cones encircle or partly encircle the shaft, and is or
are secured in position by one or more jam nuts or equivalent devices. The
propeller and cones are fitted in the factory or workshop, thus ensuring
accuracy.
Under the second part of my Invention I facilitate unshipping or removing
from their shafts of screw or stern propellers by constructing each shaft with
screwed threads, and placing a nut or nuts thereon in front of the propeller; and
I prefer that the nuts for securing and forcing off the propeller should have different
threads in direction and pitch, so that should the key or keys be sheared the said
nuts will retain the propeller in position, one nut only would be used for forcing
off the propeller. The said inner nut in front of the propeller when turned on the
thread forces the propeller from off the shaft, largely reducing the time necessary
to keep a steamer in dry or graving dock when the propeller requires to be removed
for any purpose.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Charles Jones in the Great Seal Patent Office on the 27th April
1880.
CHARLES JONES, of the Firm of John Jones and Sons, of Liverpool, in the County
of Lancaster, Engineers. " IMPROVEMENTS CONNECTED WITH SCREW PROPELLERS
FOR STEAM SHIPS."
The main objects of the said Invention are to provide means whereby screw
propellers may be more securely connected to their shafts, and also whereby they
may be more easily unshipped and shipped when necessary.
Under the first part of my Invention I ensure that screw propellers shall be
truly secured to their shafts so as to prevent breakage or other inconvenience
attending the bad fitting which is sometimes the result of the present methods of
attaching propellers on their shafts, by forming the end of the screw shaft cylin-
drical or slightly conical, and providing a collar or shoulder at the requisite
distance from the end when the said screw shaft is cylindrical, or nearly so, to
receive the thrust of the propeller when screwed up. In one modification I bore
out the boss of the propeller conically from one or both ends, and secure it in
position on the shaft by means of one or two coned bushes or clips, preferably
split, and provided with a key or keys. The said cone or cones encircles or partly
encircle the shaft, and is or are secured in position by one or more jam nuts or
equivalent devices. The propeller and cones are fitted in the factory or workshop,
thus ensuring accuracy.
Under the second part of my Invention I facilitate unshipping or removing from
their shafts of screw or stern propellers by constructing each shaft with screwed
threads, and placing a nut or nuts thereon in front of the propeller; and I prefer
that the nuts for securing and forcing off the propeller should have different threads
in direction and pitch, so that should the key or keys be sheared the said nuts will
retain the propeller in position. One nut only would be used for forcing off the
propeller. The said inner nut in front of the propeller when turned on the thread
forces the propeller from off the shaft, largely reducing the time necessary to keep
a steamer in dry or graving dock when the propeller requires to be removed for
any purpose.
DESCRIPTION OF THE DRAWINGS.
Fig. 1 is a view partly in section of so much of a propeller and its shaft as is
required to illustrate the first and second parts of my Invention.
a, screw shaft
turned cylindrical; b, nut serving as a collar or shoulder to receive the thrust of
the propeller, and also acting, under the second part of my Invention, to assist in
the removal of the propeller from its shaft; c, propeller boss bored out conically
and secured on the shaft a.by means of the conical bush or clip d; e, nut for forcing
the propeller into position; f, key.
Fig. 2 is a sectional side elevation, and Fig. 3 a cross section of a propeller boss
and its shaft, in which the shaft is turned conical, and the propeller boss c bored
cylindrical, and provided with a flange c¹; d, conical bush or clip; e, nut; f, key.
The bush or clip d has when necessary grooves g cut therein to render it more
elastic. In this case the taper of shaft renders a thrust collar unnecessary.
Fig. 4 is a sectional elevation of a further modification of propeller and boss
constructed under my Invention; here two conical bushes or clips d, d', are used
b, thrust collar.
Having now described the nature of the said Invention, and particularized the
same in such manner that others will be enabled to carry my improvements into
eflect, I claim,-
First. Securing screw propellers to their shafts, substantially as set forth.

page_text: Second. The combination of the shaft a, thrust collar b, bush or bushes, clip
or clips d, boss c, and nut or equivalent device e, for the purposes set forth.
Third. The combination of the taper shaft a, bush or bushes, clip or clips d,
boss c, and'nut e, substantially as and for the purposes set forth.
Fourth. The combination with the improvements set forth under the first part,
of the nut b, or equivalent device, for the purpose set forth.
In witness whereof, I, the said Charles Jones, have hereunto set my hand and
seal, this Twenty sixth day of April, in the year of our Lord One thousand
eight hundred and eighty.
Witness of signature,
EDWARD BATTY..
CHARLES JONES. (L.S.)