Improvements in the Means for Preventing Corrosion of Propeller Shafts.
Year: 1893

page_text: Date of Application, 9th Feb., 1893
Complete Specification Left, 9th Nov., 1893-Accepted, 13th Jan., 1894
PROVISIONAL SPECIFICATION.
Improvements in the Means for Preventing Corrosion of
Propeller Shafts.
I, WILLIAM DUMLIN, of 6 Crosby Square, in the City and County of London,..
Engineer, do hereby declare the nature of this invention to be as follows:-
This invention relates to an improved means of preventing the corrosion of
propeller shafts which takes place at the end of the brass sleeves and which causes.
the breakage and condemnation of so many shafts.
According to this invention I reduce the ends of the brass sleeves on the outer
side and cover the same and the adjacent portion of the shaft with gutta percha or
other suitable yielding material. If preferred, the middle part of the shaft from.
sleeve to sleeve may be coated with the same material.
The metal surface to be covered in this manner is first coated with a composition.
of gutta percha, glue, pitch and other ingredients conveniently known as
Charrington's compound and which is extensively used in covering telegraph wires
which will cause the covering to unite to the metal, the gutta-percha being-
applied in the same manner as it is applied to telegraph wires. Owing to the
pliability of gutta-percha, it will not crack so readily by the vibration of the shaft.
as does the red lead composition usually employed for this purpose.
TL1002
CASTLE SMITH,
Invention" Office, 54, Fleet Street, London, E.C.,
Agent for the Applicant.
COMPLETE SPECIFICATION.
Improvements in the Means for Preventing Corrosion of
Propeller Shafts.
I, WILLIAM DUMLIN, of 6 Crosby Square, in the City and County of London'
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 relates to an improved means of preventing the corrosion of
propeller shafts which takes place at the end of the brass sleeves and which causes.
the breakage and condemnation of so many shafts.
According to this invention I reduce the ends of the brass sleeves at both ends
and cover the same and the adjacent portion of the shaft for a suitable-distance
with gutta-percha. The covering on the outer end of the sleeve nearest the
propeller may be continued so as to completely cover the shaft between said sleeve.
and the propeller and also part of the propeller box. If preferred, the middle
part of the shaft from sleeve to sleeve may be coated with the same material and in
the same manner.
The metal surface to be covered in this manner is first coated with a compo-
sition of gutta-percha glue, pitch and other ingredients known as Charrington's
compound which will cause the covering to unite to the metal, the gutta-percha
being applied in the same manner as it is applied to telegraph wires. Owing
to the pliability of gutta-percha, it will not crack so readily by the vibration of
the shaft as does the red lead composition usually employed for this purpose.

page_text: And in order that my invention may be more fully understood and carried into
practice I have appended hereunto one sheet of drawings of which
Fig. 1 shews a propeller shaft coated according to my invention, and Fig. 2 a
longitudinal section taken through the liner and the covering on an enlarged scale.
As here shown the shaft is marked a, the sleeves or liners 6 and the gutta-
percha covering c. In Fig. 1 the gutta-percha covering is shown extending along
the middle part of the shaft from sleeve to sleeve.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed, I declare that what
I claim is :-
The employment of gutta-percha as a protective covering for propeller shafts
more especially at and around the junction of the same with the brass sleeve or
Fliner substantially as and for the purpose hereinbefore described and set forth and
illustrated in the accompanying drawings.
Dated this 9th day of November 1893.
CASTLE SMITH,
"Invention" Office, 54, Fleet Street, London, E.C.,
Agent for the Applicant.