Improvements in Screw Propellers.
Year: 1890

page_text: Date of Application, 3rd Mar., 1890-Accepted, 5th Apr., 1890
COMPLETE SPECIFICATION.
Improvements in Screw Propellers.
I THOMAS FISHER of Hillbrook House Holywood in the County of Down in Ireland
Paint and Colour Manufacturer 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 :-
My Invention relates to the Screw Propellers of Steam Ships and consists in
lubricating the blades thereof and thus facilitating their motion in the water so as to
increase the number of revolutions of the propeller within a given time and augment
the speed of such ships without any additional pressure on their engines.
For this purpose I form a channel or tubular duct from the boss or axial cavity of
the screw propeller to and in or upon the sides or leading edge of each blade thereof
and I perforate the blade at short intervals along the line of such channel or tubular
duct so that, when the channel or tubular duct has been charged with oil or other
lubricant, the oil or other lubricant may escape or be discharged therefrom to or upon
the sides of the blade.
The oil or other lubricant is stored in a tank or reservoir placed in any suitable
position from which the perforated channels or tubular ducts may be supplied with it
by gravitation or, if necessary, by a jet of steam or any convenient ordinary physical
or mechanical agent suitable to the purpose and I convey the oil or other lubricant from
the tank or reservoir to the perforated channels or tubular ducts by a pipe or
conduit connected with the screw shaft which is bored so as to allow the oil or other
lubricant to pass through it into and through the boss or axial cavity of the
propeller.
The connection of the pipe or conduit above mentioned with the screw shaft is
effected by means of a gland and stuffing box at any desired point upon the screw
shaft; but I prefer to run the pipe or conduit along the Rudder-post and to connect
it with the external end of the screw shaft which has, in that case, to be bored for a
very short distance and is not liable to be injured or weakened thereby. The gland
and stuffing box may either be attached to the Rudder-post and remain stationary,
with the screw shaft rotating in it, or it may be attached to the end of the screw shaft
and revolve upon the pipe or conduit.
The rotary motion of the screw propeller aids the flow of the oil or other lubricant
through the perforations in the blades and in combination with its progressive motion
causes the lubricant to spread over the sides of the blades.
And in order that my said invention may be more fully understood I shall now
proceed to refer to the drawings upon the sheet hereunto annexed the same letters of
reference being used throughout all the figures to indicate the same or corresponding
parts of my apparatus.
Fig. I is a side elevation of the stern of a screw Steam Ship showing the screw
propeller, the position of the oil tank or reservoir and the line of the pipe or conduit
conveying the lubricant along the Rudder-post to the external end of the screw
shaft.
Fig. II is an enlargement of the end of the screw shaft and of the screw propeller
shewing a part of the Rudder-post of the Steam Ship and of the pipe or conduit
crossing therefrom to the screw shaft and the gland and stuffing box connecting them,
the boring in the screw shaft from the pipe or conduit to the boss or axial cavity of
the screw propeller and the perforated channel or tubular duct from such boss or
cavity along the side or leading edge of the blade.
Fig. III is a transverse section of an enlargement of the blade of a screw propeller
showing the perforated channel or tubular duct formed by a groove cut along the
side and near to the leading edge of the blade with perforations drilled to the opposite

page_text: side thereof and also a perforated strap or plate bolted on the same side, across the
groove, in which manner my invention may be applied to existing screw propellers
and
Fig. IV is a corresponding enlargement showing the channel or tubular duct
formed by a bent plate perforated and bolted to the leading edge of the blade, in
which manner my invention may be applied to screw propellers hereafter being
constructed.
a is the oil tank or reservoir; b is the pipe or conduit conveying the lubricant
thence along the Rudder-post, c, to the end of the screw shaft, d, and connected there-
with by the stuffing box, e, which is attached, in this illustration, to the screw shaft, d;
fis the boring through the screw shaft, d, into the boss or axial cavity, 9, of the
screw propeller and is the perforated channel or tubular duct from which the
lubricant escapes or is discharged to or upon the sides of the blade, i.
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
1. The use in Steam Ships of a screw propeller arranged with blades having
perforated channels or tubular ducts constructed and employed substantially in the
manner and for the purposes hereinbefore described and shewn in the drawings
hereunto annexed.
2. The use in Steam Ships of a bored screw shaft arranged with a gland and stuffing
box and an oil pipe or conduit constructed, connected and employed substantially in
the manner and for the purposes hereinbefore described and shewn in the drawings
hereunto annexed.
3. The combination and arrangement of parts constituting my improved lubricating
apparatus constructed, connected and employed substantially in the manner and for
the purposes herein before described and illustrated by the several drawings on the
sheet hereunto annexed.
Dated this 1st day of March 1890
HYNDMAN & DICKSON,
6, Waring Street, Belfast, Agents for Applicant.