Improvements in or relating to the Protection of Shafts Exposed to Corrosive Action.
Year: 1893

page_text: Date of Application, 20th Dec., 1893
Complete Specification Left; 1st Oct., 1894-Accepted, 3rd Nov., 1894
PROVISIONAL SPECIFICATION.
Improvements in or relating to the Protection of Shafts Exposed to
Corrosive Action.
We, HENRY CROMPTON ASHLIN, of 3 Slater Road, Claughton, Birkenhead,
County of Lancaster, Consulting Engineer, and JAMES DAGLISH of 48 Arundel
Avenue, Liverpool, County of Lancaster, Consulting Engineer, do hereby declare
the nature of this invention to be as follows:-
This invention relates to the protection of shafts particularly propeller shafts of
vessels which are subject to corrosive action of gases, water, moisture or other
deleterious agents. We will describe the invention as applied to the tail or
propeller shaft of a steam vessel.
Our invention comprises especially the protecting of the shaft by means of an
enclosing casing which may be made of brass or any other suitable metal or
material and filling up the space between this casing and the shaft with any suitable
protecting agent. One way of carrying the invention into effect would be as
follows: A casing of sheet brass, Muntz metal or the like is made of a somewhat
larger diameter than the shaft to be covered and into the space between the two is
forced by means of a pump, screw or other device, red-lead, putty or other suitable
protecting cement or agent in a more or less plastic or fluid condition according to
requirement, or it may be more or less dry and granulated. The protective
material may be poured into the space from one end or from a suitable opening so
as to fill the space and then compressed or not according to circumstances, the
object being to protect the shaft with a close-fitting coating which in its turn is
protected by the outer casing. The outer casing may be applied in various ways
Bay conveniently between the stern-bush liner and the stern-gland liner being fitted
onto or into these liners in any convenient manner and brazed or otherwise firmly
secured thereto. An annular groove may be formed in the end of each liner into
which the ends of the casing may be inserted or the liner may be checked down
from the outside or the inside to receive the ends of the casing. The casing may
be made in one or more lengths and may be in more than one piece circumferentially,
brazed or otherwise connected together and may be flanged or otherwise adapted
to make a tight joint with the shaft or its couplings or with the liners. If necessary.
to keep it its proper distance all round from the shaft so as to allow of the
application of the protecting material, distance studs, indentations or other suitable
means may be provided.
Dated this 15th day of December 1893.
W. P. THOMPSON & BOULT,
Agents for the Applicants.
COMPLETE SPECIFICATION.
Improvements in or relating to the Protection of Shafts Exposed to
Corrosive Action.
We, HENRY CROMPTON ASHLIN of 3 Slater Road, Claughton, Birkenhead,
County of Lancaster, Consulting Engineer, and JAMES DAGLISH, formerly of
48 Arundel Avenue, but now residing at 44 Bagot Street Liverpool, County of
Lancaster, Consulting Engineer, do hereby declare the nature of this invention
[P1

page_text: 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 the protection of shafts particularly propeller shafts of
vessels which are subject to corrosive action of gases, water, moisture or other
deleterious agents. We will describe the invention as applied to the tail or
propeller-section of a screw shaft of a steam vessel.
Our invention comprises especially the protecting of the shaft by means of an
enclosing casing which may be made of brass or any other suitable metal or
material and filling up the space between this casing and the shaft with any suitable
protecting agent. One way of carrying the invention into effect. would be as
follows: A casing of sheet brass, Muntz metal or the like.is made of a somewhat
larger diameter than the shaft to be covered and into the space between the two is
forced by means of a pump, screw or other device, red-lead, putty or other suitable
protecting cement or agent in a more or less plastic or fluid condition according to
requirement, or it may be more or less dry and granulated. The protective
material may be poured into the space from one end or from a suitable opening so
as to fill the space and then compressed or not according to circumstances, the
object being to protect the shaft with a close-fitting coating which in its turn is
protected by the outer casing. The outer casing may be applied, in various ways
say conveniently. between the stern-bush liner and the stern-gland liner being fitted
onto or into these liners in any convenient manner and brazed or otherwise firmly
secured thereto. An annular. groove may be formed in the end of each liner into
which the ends of the casing may be inserted or the liner may be checked down
from the outside or the inside to receive the ends of the casing. The casing may
he made in one or more lengths and may, be in more than one piece circumferentially,
brazed or otherwise connected together and may be flanged or otherwise adapted
to make a tight joint with the shaft or its couplings or with the liners. If necessary.
to keep it its proper distance all round from the shaft so as to allow of the
application of the protecting material, distance studs, indentations or other suitable.
means may be provided.
In the accompanying drawings
Figure 1 is a view showing in elevation portion of a screw-propeller-shaft
protected according to our invention, the other parts shown in this figure being
represented in longitudinal section.
Figure 2 is a transverse section on the line 2-2 of Figure 1.
Figure 3 is an enlarged view of a portion of Figure 1.
Figures 4 and 5 represent alternative ways of.applying the casing.
Figures 6 and 7 are portions of transverse sections showing, alternative ways of
jointing the edges of the casing, and
Figure 8 is a transverse section showing the distance studs.
Like letters represent like parts throughout the drawings.
A is the screw-propeller-shaft to be protected against corrosive action between
the stern-bush liner B and the stern-gland liner Cat which part the water would
otherwise as ordinarily be in direct contact with it. D represents portion of the
screw-propeller-boss.
E is the casing of sheet brass, Muntz metal or other material surrounding the
shaft A at a suitable distance therefrom so as to leave an annular space between
the shaft and casing for receiving the protective material F.
The casing E may be connected to the liners B and C in any convenient manner
thus the facing ends of said liners as at B¹ and C' respectively in. Figures 1 and 3
may be grooved to receive the ends of the casing: or they may be checked down
from the outside as at B³ C' respectively in Figure 4, or, from the inside as
at B C Figure 5 to receive the, ends of E. The casing may be made in one or
more lengths and may, be in more than one piece circumferentially connected
together by, water-tight folded joints as at E' Figure 6:or-brazed'joints as at E,
Figures 7 and 8 or in any other convenient manner.

page_text: If necessary, to keep the casing Ę at its proper distance all round from or
approximately concentric with the shaft A so as to allow of a uniform thickness of
the protective agent or material F indentations E Figures 1 and 2 or distance
studs E Figure 8 or other suitable means may be employed.
Although we have herein described our invention as applied particularly to a
screw-propeller-shaft we do not limit ourselves to that application as we may apply
it to other shafts requiring similar protection, the functions of securing the
casing E in such other examples being fulfilled by collars or other devices.
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 :-
1. Protecting a shaft against corrosive action by red lead putty or equivalent
filling a space between it and a surrounding casing substantially as described.
2. The combination with a shaft of a casing surrounding it at a distance and
protective material filling the space between the shaft and casing substantially as
described.
3. In apparatus for protecting a shaft against corrosive action the employment
in combination with a casing closely surrounding a layer of protective material
which itself closely surrounds the shaft to be protected of means for maintaining
that casing at a uniform distance from the shaft.
Dated this 29th day of September 1894.
HENRY CROMPTON ASHLIN.
JAMES DAGLISH.
W. P. Thompson & Boult,
Agents for the Applicants.