Improvements in Steam or Electric After Steering Gear for Ships.
Year: 1898

page_text: PROVISIONAL SPECIFICATION.
Improvements in Steam or Electric After Steering Gear for Ships.
I, WILLIAM BRUCE THOMPSON, of Thornbank, Dundee, in the County of Forfar,
Scotland, Engineer and Shipbuilder, do hereby declare the nature of this inven
tion to be as follows:-
This invention relates to improvements in steam or electric after steering gear.
for ships, the object being to control the rudder in a simple and efficient manner.
In carrying out my invention I fix on the rudder stock a quadrant which can
move in a plane normal to the axis of such rudder stock. Mounted on the peri-
phery of the quadrant in a dovetailed groove is a curved toothed rack which can
slide backwards or forwards irrespective of the position of its supporting quad-
rant unless otherwise constrained. Springs, respectively coupled to the quadrant
and the rack may be used to provide an elastic connection between them. A
vertical shaft carried by suitable framework has upon it a spur pinion which
gears with the curved rack, such pinion being provided, if desired, with a clutch
or other disengaging gear in order to permit of the rudder being actuated by
hand, should it be found necessary. The centres of the pitch lines of the pinion
and of the curved rack may respectively coincide with the axes of the vertical
shaft and the rudder stock; or, as an alternative, the radius centre of the curved
rack may be beyond the axis of the stock, in which case the pitch line or the
periphery of the pinion will be varied to suit, that is to say the pinion and the
quadrant with its curved rack are arranged to give a varying leverage, less power
being required to actuate the rudder when amidships, than when turned to the
one side or the other. In the first case, where the pinion and the curved rack
have their centres respectively in the axes of the vertical shaft and the rudder
stock, such pinion may be made to rotate one or more times when moving the
rudder from one side to the other, but in the second case, where the pitch line
of the pinion varies to suit the curved rack of increased radius, such pinion can
only make about one complete revolution when moving the rudder from one side
to the other. On the vertical shaft is fixed a worm wheel with which gears a
worm, such worm being fixed on a horizontal shaft which can be actuated by a
horizontal or vertical steam engine of suitable design, or by an electric motor.
Dated this 17th day of December 1898.
GEO. C. DOUGLAS & Co.,
41, Reform Street, Dundee, Agents for Applicant.
Improvements in Steam or Electric After Steering Gear for Ships.
I, WILLIAM BRUCE THOMPSON, of Thornbank, Dundee, in the County of Forfar,
Scotland, Engineer and Shipbuilder, do hereby declare the nature of this inven
17

page_text: tion and in what manner the same is to be performed, to be particularly described
and ascertained in and by the following statement:-
-
This invention relates to improvements in steam or electric after steering gear
for ships, the object being to control the rudder in a simple and efficient manner.
And in order that my said invention and the manner of performing or carry-
ing the same into effect or practice may be properly understood, I have hereunto
appended three explanatory sheets of drawings in which the same reference
numerals are used to indicate corresponding parts in all the figures where shown,
that is to say:
Figure 1, (Sheet 1) is a side elevation showing the main features of my steer-
ing gear.
Figure 2, (Sheet 2) is a part plan of same.
Figure 3, (Sheet 3) is a detailed plan of the quadrant for actuating the rudder.
Figure 4, (Sheet 3) is an enlarged section at A, B, (Figure 3).
In carrying out my invention I fix on the rudder stock 10, a quadrant 11,
which can move in a plane normal to the axis of such rudder stock. Mounted
on the periphery of the quadrant in a dovetailed groove 12, is a curved toothed
rack 13, which can slide backwards or forwards irrespective of the position of
its supporting quadrant unless otherwise constrained. Springs 14, respectively
coupled to the quadrant at 15, and to the rack at 16, may be used to provide an
elastic connection between them. A vertical shaft 17, carried by suitable frame
work, as shown, has upon it a spur pinion 18, which gears with the curved rack 13,
such pinion being provided, if desired, with a clutch or other disengaging gear
in order to permit of the rudder being actuated by hand should it be found neces-
sary. As shown in the drawings the centres of the pitch lines of the pinion 18.
and of the curved rack 13, respectively coincide with the axes of the vertical
shaft 17, and the rudder stock 10. In this case, where the pinion and the curved
rack have their centres respectively in the axes of the vertical shaft and the
rudder stock, such pinion may be made to rotate one or more times when moving
the rudder from one side to the other.
On the vertical shaft is fixed a worm wheel 19, with which gears a worm 20,
such worm being fixed on a horizontal shaft 21, which can be actuated by a
horizontal or vertical steam engine of suitable design, or by an electric motor.
In the drawings I have shown a two cylinder horizontal engine, the steam sup-
ply of which is controlled by a regulator 22, in the usual way, that is to say each
cylinder has two ports, one of which acts as an admission and the other as an
exhaust port, or conversely, the general arrangement being such that say when
the regulator port 23, is open the crank shaft is made to rotate in the one direc-
tion and when the port 24, is open it is made to rotate in the other. The regu-
lator valve is actuated in a novel fashion. 31, is a shaft which is madé to rotate
in one direction or the other by means of the chain pulley 25, which is actuated
by a chain and a steering wheel or wheels suitably situated. 26, is a hand wheel
for operating the shaft should it be found necessary. 27, is a worm fixed on the
shaft, such worm gearing with the worm wheel 28, fixed on the shaft 17. The
shaft 31, is free to move laterally to some extent. 29, is a bell crank pivoted
at 30. On causing the shaft 31, to rotate, the worm tends to turn the shaft 17,
but as it is too heavy to be thus moved, the worm wheel 28, acts as a fulcrum to
such worm and consequently the shaft is made to move laterally to the one side
or the other according to the direction of rotation of the worm.
When moving
laterally it operates the bell crank 29, and consequently opens one or the other
steam admission port in the regulator, and thus the shaft 17, is rotated by means
of the worm 20, and worm wheel 19. Immediately the worm wheel 28, com-
mences to rotate it brings back the worm 27, to its normal position and so closes
the regulator port, and it remains closed until again opened in the manner
described.

page_text: Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed, I wish it to be under-
stood that although I have referred to the mode of actuating the regulator valve
in order to more clearly describe my invention, yet I lay no claim at large to
such mode, but I declare that what I claim is:-
(1) In steering gear for ships, the combination and arrangement of parts, for
actuating the rudder, substantially as described and illustrated on the annexed
drawings.
(2) In steering gear for ships, the combination of a quadrant with a sliding
toothed segment and springs for giving it the desired elasticity, substantially
as described and illustrated on the annexed drawings.
(3) In steering gear for ships, the combination of a quadrant with a sliding
toothed segment and springs, and a worm, worm wheel, and vertical shaft, as
described and for the purposes set forth.
(4) The construction, arrangement and combination of parts, substantially as
described and illustrated on the annexed drawings.
GEO. C. DOUGLAS & Co.,
Chartered Patent Agents,
41, Reform Street, Dundee, Agents for Applicant.