Improved Apparatus for Preventing the Propellers of Steam-ships from "Racing."
Year: 1889

page_text: Date of Application, 20th June, 1889
Complete Specification Left, 19th Mar., 1890-Accepted, 19th Apr., 1890
PROVISIONAL SPECIFICATION.
Improved Apparatus for Preventing the Propellers of Steam-ships
from "Racing."
I, FRANCIS GEORGE HARVEY, of Vere, in the Island of Jamaica, Civil Engineer,
do hereby declare the nature of this invention to be as follows :-
My invention relates to improved means for preventing the propellers of steam-
ships from "racing," when, owing to the pitching of the vessels to which they are
attached, the sterns of such vessels are out of the water.
My said invention consists essentially in arranging a brake, operated by hydraulic
or other fluid pressure, in conjunction with the propeller shaft, and in utilizing the
motion of the vessel for controlling the valves by means of which the supply of fluid
for operating the said brakes is necessary.
In the accompanying drawing-
Figure 1 is a side elevation of apparatus constructed according to my invention.
Figure 2 is an end view of the same; and,
Figure 3 is a vertical section on the line of fig. 1.
a is the propeller shaft, and b, b are two brake-blocks which are adapted to grip the
same, the said blocks being provided with plungers c, c entering cylinders d, d
supported on the frame e. f, f are tie-rods, which pass through lugs g, g on the
cylinders d, d, for preventing the said cylinders from moving relatively to each other.
h, h are valves for controlling the supply of fluid to the cylinders d, d.
i is a weighted arm or lever which is suspended from the shaft ; carried in
bearings k, k on the frame e. At each end of the shaft j is a lever-arm 1 connected
by a link m to the stem n of one of the valves h, h in such a manner, that, when
motion is communicated to the shaft j, the said valves will be operated. The
weighted arm i is suspended between guide-plates o, o so that it is not affected by any
rolling motion of the vessel, and so that it will only operate the valves when the stern
of the vessel rises out of the water. When the bow of the vessel is higher than the
stern the weight on the said arm is supported against one side of the frame e, a
cushion p being arranged to prevent the weight from forcibly striking the said frame
during the lurching of the vessel.
It will be readily understood that if the stern rises so that the frame e assumes an
inclined position, for instance, as indicated by dotted lines in fig. 3, the weighted arm,
by remaining in a vertical position, will cause the operation of the valves h, h to
admit fluid into the cylinders d, d, whereby the blocks b, b will be forced tightly
against the propeller-shaft and compensate for the non-resistance of the water;
immediately the vessel assumes such a position that the shaft of the propeller again
enters the water, the valves are again operated to shut off the supply of fluid and to
permit the discharge of the fluid contained in the cylinders, so that springs 9, 9
arranged between the blocks b, b will force the latter away from the propeller-shaft.
Dated the 20th day of June 1889.
40
G. F. REDFERN & Co.,
4, South Street, Finsbury, London, Agents for the Applicant.
COMPLETE SPECIFICATION.
Improved Apparatus for Preventing the Propellers of Steam-ships
from "Racing."
I, FRANCIS GEORGE HARVEY, of Vere, in the Island of Jamaica, Civil Engineer,
do hereby declare the nature of this invention and in what manner the same is to
[Price 6d.]

page_text: "
be performed to be particularly described and ascertained in and by the following
statement:-
My invention relates to improved means for preventing the propellers of steam-
ships from "racing," when, owing to the pitching of the vessels to which they are
attached, the sterns of such vessels are out of the water.
My said invention consists essentially in arranging a brake, operated by hydraulic
or other fluid pressure, in conjunction with the propeller-shaft, and in utilizing the
motion of the vessel for controlling the valves by means of which the supply of fluid
for operating the said brakes is necessary.
In the drawing accompanying my Provisional Specification-
Figure 1 is a side elevation of apparatus constructed according to my invention.
Figure 2 is an end view of the same; and,
Figure 3 is a vertical section on the line x x of fig. 1.
a is the propeller-shaft, and b, b are two brake-blocks which are adapted to grip the
same, the said blocks being provided with plungers c, c entering cylinders d, d sup-
ported on the frame e. f, fare tie-rods, which pass through lugs 9, 9 on the
cylinders d, d, for preventing the said cylinders from moving relatively to each other.
h, hare valves for controlling the supply of fluid to the cylinders d, d.
i is a weighted arm or lever which is suspended from the shaft ; carried in
bearings k, k on the frame e. At each end of the shaft j is a lever arm connected by
a link m to the stem n of one of the valves h, h in such a manner, that when motion is
communicated to the shaft j; the said valves will be operated. The weighted arm i is
suspended between guide-plates o, o so that it is not affected by any rolling motion of
the vessel, and so that it will only operate the valves when the stern of the vessel rises out
of the water. When the bow of the vessel is higher than the stern the weight on the
said arm is supported against one side of the frame e, a cushion p being arranged to
prevent the weight from forcibly striking the said frame during the lurching of the
vessel.
It will be readily understood that if the stern rises so that the frame e assumes an
inclined position, for instance, as indicated by dotted lines in fig. 3, the weighted arm,
by remaining in a vertical position, will cause the operation of the valves h, to
admit fluid into the cylinders d, d, whereby the blocks b, b will be forced tightly
against the propeller shaft and compensate for the non-resistance of the water;
immediately the vessel assumes such a position that the shaft of the propeller again
enters the water, the valves are again operated to shut off the supply of fluid and to
permit the discharge of the fluid contained in the cylinders, so that springs 9, q
arranged between the blocks b, b will force the latter away from the propeller-shaft.
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed, I declare that what I
claim is :-
(1.) Braking the shaft of the propeller of a steam-ship to compensate for the
non-resistance of the water, and utilizing the motion of the vessel for controlling
the application of the brake power, substantially as, and for the purpose, described.
(2.) In apparatus for utilizing the motion of a vessel for applying a brake to
the propeller shaft, the combination of brake-blocks adapted to be forced into
contact with the said shaft by fluid pressure, valves for controlling the supply of
fluid for actuating such brakes, and a shaft carrying a weighted arm, the said shaft
being connected with the stems of the valves, all substantially as described.
(3.) The improved apparatus herein before described and illustrated in the accom-
panying drawing for preventing the "racing" of the propellers of steam-ships.
1000
G. F. REDFERN & Co.,
4, South Street, Finsbury, London, Agents for the Applicant.