Year: 1888

page_text: Date of Application, 31st Jan., 1888
Complete Specification Left, 29th Oct., 1888
Complete Specification Accepted, 30th Nov., 188
We, JOHN STEAD, of 4 Winstanley Crescent, Margate Road, Ramsgate, in the
county of Kent, and THOMAS LANGDON ROBERTS, of Rookhurst, Tavistock Road,
Croydon, in the county of Surrey do hereby declare the nature of this invention to be
as follows:-
-
This our invention relates to certain new and useful improvements in Screw-
Propellers, and which invention has for its object to provide a Screw-Propeller which
will cleave and deliver the water clearer than those hitherto known and constructed.
A further advantage occasioned by our improved Screw-Propeller consists in the
steady running of the machinery and the consequent lessening of vibration of the
vessel. Our invention may be described as follows
The blades, of which there are preferably four, consist of metal plates, each of which
is of determined width and length. The width of the said blades is greatest at their
centre and tapers down towards their outside edges, one edge being formed with a
shank or tenon for the purpose of attachment to the boss of the propeller. The
blades thus shaped are slightly hollowed upon their face as has hitherto been the
custom. When the blades have been set at the required pitch, the back-water from
one blade is thrown upon the face of the other blade, and by this operation a steady
motion of the propeller and shaft is ensured.
Dated this Thirty-first day of January 1888.
REGINALD W. BARKER,
Agent on behalf of Applicants.

page_text: An Improved Screw-propeller.
We, JOHN STEAD, of Winstanley Crescent, Margate Road, Ramsgate, Sailor and
THOMAS LANGDON ROBERTS, of "Rookhurst," Tavistock Road, Croydon, no occupation
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 our invention relates to certain new and useful improvements in Screw-
Propellers, and which invention has for its object to provide a Screw-Propeller
which will cleave and deliver the water clearer than those hitherto known and
constructed, and moreover to ensure steadiness in the running of the machinery
and thereby diminishing the wear and tear thereof, and consequently lessening the
vibration of the vessel.
We now proceed to describe our said invention, reference being had to the
accompanying drawings, and the figures and letters of reference marked thereon,
similar letters indicating like parts throughout.
Fig. 1 is a perspective clevation of our improved Screw-Propeller.
Fig. 2 is a plan of one of the blades, and Fig. 3 is a sectional elevation taken on
the line of Fig. 2.
•
In this our said invention the blades A, of which there are preferably four, are
formed in the shape shown in figs. 1 & 2 viz. :-their greatest width at or about
midway their length. The blades A are made somewhat hollow upon their front
face, as will be seen by reference to Fig. 3, this being for the purpose of enabling
them to retain a better hold of the water. A collar B and screw-tenon C, or other
well-known means of attachment, enable the blades to be screwed into the boss D.
It is an essential feature of our invention that the blades should be set at the
required angle viz. :-51° or thereabouts.
By the peculiar construction of this our improved Screw-Propeller the backwater
from one blade is thrown upon the face of the other blade and by this operation the
steadiness of the machinery and propeller is attained.
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
A Screw-Propeller having blades of the shape shown in the drawings, said blades
having their faces hollowed out, set at an angle of or about 51°, and formed with a
collar and screw-tenon or other means of attachment whereby they may be fitted to
the boss, all substantially as and for the purposes hereinbefore described and
illustrated in the drawings hereunto annexed.