Improvements in Means or Devices for Preserving the Tail Shafts of Steamers, and other Shafts, from Corrosion.
Year: 1892

page_text: Date of Application, 9th Sept., 1892
Comolete Specification Left, 5th May, 1893-Accepted, 27th May, 1893
PROVISIONAL SPECIFICATION.
Improvements in Means or Devices for Preserving the Tail Shafts
of Steamers, and other Shafts, from Corrosion.
I, THOMAS MUDD, of The Central Marine Engine Works, West Hartlepool, in
the County of Durham, Marine Engineer, do hereby declare the nature of this
invention to be as follows:-
This invention has for its object an apparatus for preserving shafts from corrosion,
and is designed especially for preserving the tail shafts of steamers from the action
of the water to which they are constantly exposed.
In carrying my invention into effect, the plan which I prefer is to encase the
exposed part of the shaft in a tube of india-rubber or other suitable elastic
material, so that the said tube will contract closely upon the shaft, keeping it free
from the action of water, the shaft being preferably first coated with tar cement
or varnish, so that the tube may adhere closely thereto.
The tube may be intact and drawn over the end of the shaft or it may be
lapped round the shaft and united into a tube in situ.
It may be further protected on the outside, and kept more firmly in place by
lapping with wire.
Dated this 8th day of September 1892.
WM. P. THOMPSON & Co.,
Of 6, Lord Street, Liverpool, Patent Agents for the Applicant.
COMPLETE SPECIFICATION.
Improvements in Means or Devices for Preserving the Tail Shafts
of Steamers, and other Shafts, from Corrosion.
I, THOMAS MUDD of The Central Marine Engine Works, West Hartlepool, in
the County of Durham, Marine 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 :-
This invention has for its object an apparatus for preserving shafts from
corrosion, and is designed especially for preserving the tail shafts of steamers
from the action of the water to which they are constantly exposed.
In carrying my invention into effect, the plan which I prefer is to encase the
exposed part of the shaft in a tube of india-rubber or other suitable elastic
material, so that the said tube will contract closely upon the shaft, keeping it free
from the action of water, the shaft being preferably first coated with tar, cement
or varnish, so that the tube may adhere closely thereto.
The tube may be intact and drawn over the end of the shaft or it may be lapped
round the shaft and united into a tube in situ.
It may be further protected on the outside, and kept more firmly in place by
lapping with wire or other material.
In the drawings-
AA are the brass liners; B, the coating of india rubber, gutta percha, woodite,
tough bitumen or mixed bitumen and fibre or other elastic or tough adherent water-
proof material. This is caused to adhere, not merely to the exposed parts of the
shaft itself, but to the liners also, which are preferably tapered with a long taper
as shown, so that the surface of the material can be continuous with the surface of
the liner or nearly so and yet have a long bearing on the liner itself.

page_text: It is important that the elastic sleeve make a watertight joint over the part
where the liner meets the shaft, thus preventing that galvanic action between the
two metals in the presence of water which is an important cause of corrosion.
The exposed parts of shafts between bosses of water wheels and the sleeves in
bearings, or between any two parts keyed or shrunk on a shaft revolving in or
exposed to wet, can be coated in this way, while, even in the case of two such
parts touching each other, fixed on the same shaft, the crack between can be
covered over in this manner to prevent water entering by capillary attraction or
otherwise. Where the bearing is not long, it is well to bandage such covering with
wire or other material to keep it from being knocked off.
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 :-
:-
The improvement in means or devices for preserving the tail shafts of steamers
or other shafts from corrosion arising directly, or indirectly through galvanic
action, which consists in covering the part exposed to these dangers with india-
rubber, gutta percha or a mixture thereof, or other similar tough, elastic, water-
proof composition or material, substantially as and for the purposes described.
Dated this 4th day of May 1893.
WM. P. THOMPSON & Co.,
Of Liverpool, Manchester, Nottingham, and London, Patent Agents.