IMPROVEMENTS IN SHAFT BEARINGS
Year: 1857

page_text: LETTERS PATENT to David Patridge, of Tavistock Place; Plumstead
Common, Woolwich, for the Invention of "IMPROVEMENTS IN SHAFT
BEARINGS."
Sealed the 9th April 1858, and dated the 19th October 1857.
PROVISIONAL SPECIFICATION left by the said David Patridge at the
Office of the Commissioners of Patents, with his Petition, on the 19th
October 1857.
..
I, DAVID PATRIDGE, of Tavistock Place, Plumstead Common; Woolwich,
do hereby declare the nature of the Invention for "IMPROVEMENTS: IN. SHAFT
BEARINGS," to be as follows:-
This Invention has for its object improvements in shaft. bearings, and it is
applicable more especially to the bearings of the screw shafts of steam vessels
and to other bearings which are exposed to the action of water. Bearings of
the ordinary description when exposed to the action of water constantly falling
on them, as is the case with screw shafts, quickly become unserviceablet from
the oxidation and consequent roughening of the surface of the shaft, which
causes the brasses to be rapidly cut away. Now, according to my Invention
I obviate this difficulty by coating the shaft at the bearing with tin or soft

page_text: metal, so as effectually to protect it from the action of the water, and at the
same time to give it a surface which turns with little friction in its brasses or
supports.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said David Patridge in the Great Seal Patent Office, on the 16th
April 1858.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, DAVID
PATRIDGE, of Tavistock Place, Plumstead Common, Woolwich, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Nineteenth day of October, in the year of Our Lord
One thousand eight hundred and fifty-seven, in the twenty-first year of Her
reign, did, for Herself, Her heirs, and successors, give and grant unto me, the
said David Patridge, Her special licence, that I, the said David Patridge, my
.executors, administrators, and assigns, or such others as I, the said David
Patridge, my executors, administrators, and assigns, should at any time agree
with, and no others, from time to time and at all times thereafter during the
term therein expressed, should and lawfully might make, use, exercise, and
vend, within the United Kingdom of Great Britain and Ireland, the Channel
Islands, and Isle of Man, an Invention for "IMPROVEMENTS IN SHAFT BEARINGS,"
upon the condition (amongst others) that I, the said David Patridge, my
executors or administrators, by an instrument in writing under my, or their,
or one of their hands and seals, should particularly describe and ascertain the
nature of the said Invention, and in what manner the same was to be per-
formed, and cause the same to be filed in the Great Seal Patent Office within
six calendar months next and immediately after the date of the said Letters
Patent.
NOW KNOW YE, that I, the said David Patridge, do hereby declare the
nature of the said Invention, and in what manner the same is to be performed,
to be particularly described and ascertained in and by the following statement
thereof, that is to say:-
This Invention has for its object improvements in shaft bearings, and it is
applicable more especially to the bearings of the screw shafts of steam vessels
and to other bearings which are exposed to the action of water. Bearings of
the ordinary description when exposed to the action of water constantly falling

page_text: on them, as is the case with screw shafts, quickly become unserviceable from
the oxydation and consequent roughening of the surface of the shaft, which
causes the brasses to be rapidly cut away. Now, according to my Invention I
obviate this difficulty by coating the shaft at the bearing with tin or soft
metal, so as effectually to protect it from the action of the water, and at the
same time to give it a surface which turns with little friction in its brasses or
supports.
Having thus stated the nature of my said Invention, I will proceed more
fully to describe the manner of its application.
DESCRIPTION OF THE DRAWING.
Figure 1 shows an intermediate shaft such as is used on board steam boats
and vessels propelled by a screw or submerged propeller. a, a, is the shaft ;
a, a', are the cranks, and a², a², are the crank pins; b, b, are the parts of the
shaft which are coated with soft metal, such as has been before used in the
boxes or hollow bearings in which shafts or axes have turned. Figure 2 is a
shaft of a screw propeller where the propeller is fixed near the end of the
shaft. b, b, b, are the parts of the shaft which are coated with tin or soft
metal. Figure 3 shows another shaft suitably arranged for the screw or
submerged propeller, being detached at the clutch d, as is well understood;
b, b, b, are the parts of the shafts which are coated with tin or soft metal; e is
a coupling clutch; and f is a fixed tube in which the shaft rotates.
In order to apply the tin or soft metal at the bearing parts b, b, of the
several shafts shown, or of similar bearing parts of other shafts, such parts b
are first cleaned, then pickled, and then tinned, as is well understood when
tinning the surfaces of other articles made of iron. Such surfaces of the
shafts having been tinned they are introduced into suitable moulds; the melted
tin or soft metal is then poured into the moulds, and is if necessary after-
wards reduced to the desired thickness or diameter by means of a lathe. Care
is taken to make the shaft sufficiently hot to cause the metal poured into the
moulds to combine with the coating of tin already on the shaft from the
process of tinning, as the thickness of metal required even for large shafts is
not more than 1th of an inch, and for smaller shafts it is less. Shafts thus
coated will be found to be preserved from oxidation in their bearings, and
they will be found to work better than heretofore in brasses or other hard
metal, or in lignum vitæ or other wood.
Having thus described the nature and mode of application of my said

page_text: Invention, I would have it understood that what I claim is, coating, chemically
the bearing parts of propeller and other shafts, with tin or soft metal, as herein
¡described.
In witness whereof, I, the said David Patridge, have hereunto set my
hand and seal, this Fourteenth day of April, in the year of our Lord
One thousand eight hundred and fifty-eight.
Witness,
FREDERIC DUTTON.
D. PATRIDGE. (L.S.)