Improvements relating to Ships' Propellers.
Year: 1895

page_text: Improvements relating to Ships' Propellers.
I, MANASSAH GLEDHILL, Director of Sir Joseph Whitworth & Co., Limited,
of Openshaw, Manchester, in the County of Lancaster, Engineer, do hereby
declare the nature of this invention to be as follows:-
My invention relates to ships' propellers and consists in a novel method of
providing a boss or hub on the propeller shaft for the attachment of the blades.
A ship's propeller as now ordinarily constructed consists of the boss and a
series of blades which are separately formed and are fitted in recesses in the said
boss and secured thereto by screw bolts.
Heretofore it has been customary to cast or otherwise form the said boss
separately and fit it upon the end of the stern shaft which is preferably made
taper, the boss being secured by keys or other suitable devices to the said taper
end of the shaft.
According to my invention, however, I forge the boss solidly or in one piece
with the end of the tail or stern shaft. That is to say I forge on the end of
the shaft, by the aid of suitable dies or swages, a spherical portion of the required
diameter and then by suitable tools form thereon the necessary flat faces and
bore out the holes and recesses for the reception of the propeller blades which
I propose to construct and secure to the boss in the ordinary or any convenient
manner.
By this invention I obviate the danger which has hitherto existed of, the loss
of the entire propeller by the detachment of the boss from the shaft. Moreover
I avoid the weakening of the shaft due to the formation of key ways therein
and greatly economize the production of the shaft and boss.
I can also by this invention insert a plug or bar of specially strong steel into
the propeller end of the shaft, so that if the shaft should break at this part the
said plug or bar would still maintain the propeller boss in position and therefore
prevent it and the propeller from falling into the sea.
My invention may be very advantageously applied to a propeller with feathering
blades, operated by a central shaft extending from the boss through the hollow
propeller shaft to the engine room, as the above described method of forming
the boss on the shaft allows a clear space in the centre of the same for the
mechanism which connects the blades with the said central shaft.
Dated this 10th day of Auquet 1895
HASELTINE, LAKE & Co.,
45 Southampton Buildings, London, W.C., Agents for the Applicant.

page_text: Improvements relating to Ships' Propellers.
I, MANASSAH GLEDHILL, Director of Sir Joseph Whitworth & Co. Limited,
of Openshaw, Manchester, in the County of Lancaster, Engineer, 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 :-
My invention relates to ships' propellers and consists in a novel method of
providing a boss or hub for the attachment of the blades.
A ship's propeller ordinarily consists of the boss and a series of blades which are
separately formed and are fitted in recesses in the said boss and secured thereto by
screw-bolts. Heretofore it has been customary to cast or otherwise form the said
boss separately and fit it upon the end of the stern shaft which is preferably made
taper, the boss being secured by keys or other suitable devices to the said taper
end of the shaft.
According to my invention, however, I forge the boss solidly or in one piece
with the end of the tail or stern shaft. That is to say, I forge on the end of the
shaft, by the aid of suitable dies or swages, a spherical or other suitably shaped
protuberance of the required dimensions and then by suitable tools form thereon
the necessary flat faces and bore out the holes and recesses for the reception of the
propeller blades which I propose to construct and secure to the boss in the ordinary
or any convenient manner.
My invention is illustrated in the accompanying drawings in which
Figure 1 is a side view of a portion of a shaft with a spherical hub or boss
forged thereon according to my invention and faced and recessed for the reception
of three blades.
Figure 2 is a rear end view of the same.
Figure 3 is a transverse section on the line a Figure 1.
Figure 4 is a longitudinal central section of the propeller shaft and boss shown
in Figure 1.
Figure 5 is a side elevation of a portion of a shaft with a square boss forged
thereon and fitted for the reception of four blades.
Like letters indicate the same parts throughout the drawings.
A is the shaft, A¹ is the enlarged portion forming the boss or hub. B, B are
the recessed flat portions for the reception of the blades. CC are holes
extending inward from the recesses and intended to receive the shanks of the
propeller blades. The shaft may be either hollow or solid but in the drawings
I have shewn a hollow shaft with a plug or bar D inserted in the central aperture
thereof. This plug should be made of specially strong steel so that if the
shaft A should break at this part as indicated at a the said plug or bar would
retain the propeller boss in its position on the shaft and therefore prevent its
falling with the propeller blades into the sea.
My invention may be very advantageously applied to a propeller with feathering
blades, operated by a central shaft extending from the boss A¹ through the hollow
propeller shaft to the engine room, as the above described method of forming the
boss on the shaft allows a clear space in the centre of the same for the mechanism
which connects the blades with the said central shaft.
By my invention I obviate the hitherto existing danger of the loss of the entire
propeller by the detachment of the boss from the shaft. Moreover I avoid the
weakening of the shaft due to the formation of key-ways therein and greatly
economise the manufacture of the shaft and boss.

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
claim is :-
1. A propeller shaft with a spherical or other protuberance forged on the end
thereof and provided with recesses and holes substantially as described for the
purpose specified.
2. A ship's propeller consisting of a series of blades secured to a boss or hub
forged on the end of the stern shaft.
3. A hollow shaft having a boss or protuberance forged on the end thereof and a
central plug or bar inserted within the same substantially as, and for the purpose,
specified.
Dated this 11th dan SM 1900
HASELTINE, LAKE & Co.,
45 Southampton Buildings, London, W.C., Agents for the Applicant.