Improvements in or relating to Steering Gear for Vessels.
Year: 1899

page_text: Date of Application, 21st Dec., 1899-Accepted, 7th Apr., 1900
COMPLETE SPECIFICATION.
Improvements in or relating to Steering Gear for Vessels.
THE ABBÉ ALFRED PIEDFORT, Professor, of 24, Rue du Fourachaux, Calais
(Pas de Calais), in the Republic of France, 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:-
The present invention relates to a multiplying or power transmission mechanism
for the purpose of working, with very little power, a rudder swinging round a
vertical horizontal or oblique axis, irrespective of the dimensions or weight of the
rudder.
This gearing mechanism enables if necessary, the assistance of auxiliary motors
worked by steam, compressed air or other fluid to be dispensed with, the rudder
being effectively worked irrespective of the season or of the tonnage of the
vessel.
In the present application of the improved steering gear mechanism for working
at a distance-a case chosen by way of example-it is assumed that the steersman
effects the steering by sending through an electric motor M, capable of working in
either direction, either a positive or negative current, according as to whether it
is intended to cause the rudder to turn to the right or to the left; it should
however, be understood, that the invention relates particularly to the multiplying
or power transmission gearing, and that the steersman may just as well, work it
by suitably actuating a steering wheel in the ordinary manner.
Figure of the accompanying drawing represents a side elevation of the
multiplying gear as applied to a rudder, the mechanism being actuated by
sending through the motor M a positive or negative current according to the
direction in which the rudder is intended to be turned.
Figure 2 is a plan view of the same, and
Figure 3, is a view or diagram of an ordinary steering wheel transmitting its
rotary movement through a shaft e, thereby effecting the angular rotation of
the multiplying gear in the direction required.
The rudder is mounted in the ordinary way on its stem and is actuated as
usual, by a chain or tiller rope p p passing round the drum or barrel s to which
it is fixed at .. The tiller chain or rope is connected at y and g with multiplying
or power transmission gear chains or equivalent and respectively, of which
the size of links or dimensions gradually become less from the said points 7
of attachment to the points where they are connected to a slight chain or cord
passing once round a wheel drum or a toothed sector keyed on a vertical shaft i.
The chains n¹ are passed several times round a drum or barrel m, which is
rotated in a continuous and uniform manner at a speed of about one revolution
per second, in the direction indicated by the arrows d without, however, involving
in this movement the chains which are wound on in an opposite direction to
that indicated by the arrows. the drum normally simply rotating within the
chains without appreciable friction.
The shaft, on which is keyed the wheel or toothed sector
participates in
the movement of the wheel k by means of a wheel h with helicoidal teeth which
gear with an endless screw or worn f on a horizontal shaft c.

page_text: In Figures 1 and 2 it is assumed, that the angular displacement of the wheel
or toothed sector which is proportional to the desired deflection of the rudder.g,
is obtained by means of a small electric motor M, capable of turning in one or
the other direction according to the direction in which the current is caused to
flow through the motor. The shaft o of the motor M is provided with a pulley c
which transmits its rotary movement by means of a belt, cord or chain, to a
pulley keyed on the worm shaft e.
The arrangement represented in Figure consists of an ordinary steering
wheel on a shaft o on which is keyed a chain wheel c, actuating by means of a
chain a second chain wheel keyed on the shaft c.
When the steersman desires to turn the rudder to the right he presses on a
commutator which will send a current of the required direction through the
motor M. capable of setting in rotation the shaft and with it the pulleys c
and d, the worm f the helicoidal wheel and the toothed wheel thereby,
putting a tensional strain on one of the chains or cords or in one direction and
slackening at the same time the other chain or cord or respectively in the
opposite direction. This weak power effect is multiplied in passing through the
corresponding multiplying chain or ', owing to the continuous rotation of the
drum m, in consequence of which the corresponding tiller rope or is
actuated, resulting finally in the rotary movement of the rudder shaft head s,
and of the rudder. This displacement is effected very rapidly and is continued
until the steersman ceases to send the electric current through the motor.
The reverse effect is produced when the steersman sends through the motor a
current in the reverse direction.
The rotation of the shaft e and the parts connected with it may also be pro-
duced, as before stated, by working a steering wheel in the ordinary manner.
The angular movements of the shaft and those of the rudder may also be
effected by employing, instead of a worm f, a wheel with helicoidal teeth, on
the shaft actuated directly by the steersman; or the worm and worm wheel
device may be replaced by a suitable conical or bevel wheel gearing.
The chains or cords need not be under tension when at rest as the effect of
the multiplying gear chains n¹ will be just the same, one or other of the
chains will be drawn taut as soon as the motor is started.
The continuous rotary movement of the chain drum m is effected by power from
any suitable motor power of the vessel.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed, I declare that what
I claim is:
1
1. A power transmission gear capable of effecting, at a distance, the required
movements of a rudder, characterized by the connection of the tiller chain or
rope with two chains or equivalent, the dimensions of which gradually decrease
from their points of attachment to the tiller chain or rope, to the points of attach-
ment to a light chain or cord passing round a wheel or a toothed sector or drum
mounted on a shaft capable of receiving an angular rotary movement from the
steersman, either by hand or by motor power, the said chains being wound round a
drum revolving continuously in the opposite direction to that in which the said
chains are wound round it, on the surface of which they slide normally with
slight friction.
2. The complete power transmission gear for steering vessels substantially as
described or illustrated in the accompanying drawings.
Dated this 21st day of December 1899.
BOULT, WADE & KILBURN,
Agents for the Applicant.