IMPROVEMENTS IN THE MANUFACTURE OF SCREW PROPELLERS, AND IN APPARATUS EMPLOYED THEREIN."AL SPFIC
Year: 1881

page_text: LETTERS PATENT to Thomas Turton, of Liverpool, in the County of Lancaster,
Iron and Steel Manufacturer, and George Allibon, of the same Place, Engineer,
for an Invention of "IMPROVEMENTS IN THE MANUFACTURE OF SCREW
PROPELLERS, AND IN APPARATUS EMPLOYED THEREIN."
PROVISIONAL SPECIFICATION left by the said Thomas Turton and George
Allibon at the Office of the Commissioners of Patents on the 27th May
1881.
THOMAS TURTON, of Liverpool, in the County of Lancaster, Iron and Steel
Manufacturer, and GEORGE ALLIBON, of the same Place, Engineer. "IMPROVE-
MENTS IN
THE MANUFACTURE OF SCREW PROPELLERS, AND IN APPARATUS
EMPLOYED THEREIN."
Pitting and corrosion of iron and steel propellers, more especially on the
following surfaces of the blades, not only reduces the ultimate strength to resist
fracture but materially interferes with efficiency. To prevent pitting and corrosion
and to provide screws with a surface offering less friction in the water is the
object of our Invention.
We cast or construct iron or steel propellers in any ordinary way, and after
pickling and cleaning them by acids or otherwise we dip them in a bath of molten
zinc or like metal, in that way giving them a protective coating and a smooth
surface.
The apparatus employed to obviate the necessity for melting a very large
quantity of metal consists of a bath constructed with radial bays, each to receive
one blade of the propeller. These bays unite at the centre where the boss of the
screw rests. This apparatus is useful when the screw is rested on its side during
the process of coating.
To provide light and economical plant for coating we sling the screw and dip
blade after blade into deep vessels, one containing the acid and another the molten
metal.
Our Invention is applicable as will be evident to the coating of screws now
in use.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said Thomas Turton and George Allibon in the Great Seal Patent
Office on the 26th November 1881.
THOMAS TURTON, of Liverpool, in the County of Lancaster, Iron and Steel
Manufacturer, and GEORGE ALLIBON, of the same Place, Engineer. "IMPROVE-
MENTS IN THE MANUFACTURE OF SCREW PROPELLERS, AND IN APPARATUS
EMPLOYED THEREIN."
Pitting and corrosion of iron and steel propellers, more especially on the
following surfaces of the blades, not only reduces the ultimate strength to resist
fracture, but materially interferes with efficiency. To prevent pitting and corrosion
and to provide screws with a surface offering less friction in the water is the object
of our Invention.
We cast or construct iron or steel propellers in any ordinary way, and after
pickling and cleaning them by acids or otherwise we dip them in a bath of molten
zinc or like metal, in that way giving them a protective coating and a smooth
surface.
The apparatus employed to obviate the necessity for melting a very large
quantity of metal consists of a bath constructed with radial bays each to receive
one blade of the propeller. These bays unite at the centre where the boss of the
screw rests. This apparatus is useful when the screw is rested on its side during
the process of coating.
To provide light and economical plant for coating we sling the screw and dip
blade after blade into deep vessels, one containing the acid and another the molten
metal.
Our Invention is applicable as will be evident to the coating of screws now
in use.
DESCRIPTION OF THE DRAWINGS.
Fig. 1 is a plan of apparatus suitable for use in coating a screw propeller with
zinc or protecting metal at one operation. The apparatus consists of a bath a
constructed with radial bays b united at the centre; the propeller & lies in the
centre of trough or bath and the blades in the radial bays. Troughs constructed
substantially as shown have radial bays equal in number to the blades of the
propeller to be coated, and may advantageously be of varying sizes so as to allow of
the minimum quantity of metal being fused for coating any given sized propeller.
Fig. 2 illustrates apparatus in which the propeller is held in a vertical instead of
in a horizontal position whilst being coated.
This apparatus is specially applicable where there is not space or means for
using the horizontal bath hereinbefore described; e, bath for acid; f, bath for
molten zinc or like metal; g, propeller carried on the shaft h; i, shackle attached
to the shaft h, and of such size as to admit of the propeller being turned round on
the said shaft. The blades of the propeller are dipped one after the other alternately
into the baths e and f. Cranes, winches, or other suitable apparatus is used for
raising, lowering, and moving the propellers. It will be evident that loose propeller
blades may be coated by the above described apparatus.
Having now particularized and ascertained the nature of our said Invention in
such manner that others will be enabled to carry our improvements into effect,
we claim,―
First. The manufacture of screw propellers, substantially in the manner and for
the purposes setforth.

page_text: Second. The apparatus substantially as herein described and illustrated for the
purposes setforth.
In witness whereof, I, the said Thomas Turton, have hereunto set my hand
and seal, this Twenty fourth day of November, in the year of our Lord
One thousand eight hundred and eighty one.
JAMES JOHNSON,
Patent Office,
4, Clayton Sqr.,
Liverpool.
Witness.
QUOTTI
ORION.
(L.S.)