Improvements in Steering Gear for Ships and Boats.
Year: 1895

page_text: Date of A plication, 28th June, 1895
Complete Specification Left, 24th Mar., 1896-Accepted, 25th Apr., 1396
PROVISIONAL SPECIFICATION.
Improvements in Steering Gear for Ships and Boats.
I, WILLIAM HORATIO HARFIELD, of Mansion House Buildings, Queen
Victoria Street, in the City of London, Mechanical Engineer, do hereby declare the
nature of this invention to be as follows:-
This invention relates to further improvements in steering gear for ships and
boats of the kind described in the Specification of my former Patent No. 11560
of 1889, that is to say, wherein the available operating power is proportioned or
distributed according to the work to be done or the resistance to be overcome.
Steering gear constructed according to my former Patent has given excellent
results in practice, but in some cases gear, which can be produced at less cost, is
required, and the object of my present improvements is to meet this requirement.
For this purpose instead of employing as in my former Patent a toothed rack
formed or curved to gear with the teeth of an eccentric or cam-shaped pinion I employ
a chain which is passed round an eccentric chain wheel, the ends of the chain being
connected respectively to the outer ends of arms on the rudder post.
The eccentric chain wheel is carried on a spindle and (like the eccentric or
cam-shaped pinion described in my former Patent) is so placed that, when the tiller
is amidships, the side of the eccentric chain wheel of the longer or larger radius
pulls upon the chain and when the tiller is being moved over to "port" or to
starboard" the side of the eccentric chain wheel of shorter radius pulls on the
chain and acts on the tiller, thereby obtaining similar results to those obtained by
the use of my said former Patent.
It is essential that the chain wheel should be so shaped that the chain is always
taut in all positions.
Dated this 28th der of June 1905
Improvements in Steering Gear for Ships and Boats.
I, WILLIAM HORATIO HARFIELD, late of Mansion House Buildings, Queen
Victoria Street, in the City of London, but now of Arundel House, Thames
Embankment, in the County of London, Mechanical Engineer, 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 invention relates to further improvements in steering gear for ships and
boats of the kind described in the Specification of my former Patent No. 11560
of 1889, that is to say, wherein the available operating power is proportioned or
distributed according to the work to be done or the resistance to be overcome.
Steering gear constructed according to my former Patent has given excellent
results in practice but, in some cases, gear, which can be produced at less cost, is
required and the object of my present improvements is to meet this requirement.
07

page_text: For this purpose instead of employing as in my former Patent a toothed rack
formed or curved to gear with the teeth of an eccentric or cam-shaped pinion I
employ a chain which is passed round an eccentric chain wheel, the ends of the
chain being connected respectively to the outer ends of arms on the rudder post.
"
The eccentric chain wheel is carried on a spindle and (like the eccentric or
cam-shaped pinion described in the Specification of my former Patent) is so placed
that, when the tiller is amidships, the side of the eccentric chain wheel of the longer
or larger radius pulls upon the chain and when the tiller is being moved "to port
or "to starboard" the further it is moved over "to port' or to starboard the
shorter the radius of pull on the chain becomes, thereby obtaining similar results to
those obtained by the use of my said former Patent.
"
It is essential that the chain wheel should be so shaped that the chain is always
taut in all positions.
In order to enable my invention to be fully understood I will describe the same
by reference to the accompanying drawing, in which
―
Figure 1 is a plan of the steering gear with the tiller in the amidships position,
and
Figure 2 is a plan with the tiller "hard over."
"
a indicates the rudder post and b, the tiller arms fixed thereon.
c is the
eccentric chain wheel fixed upon the shaft d. e is the chain which is passed round
the eccentric chain wheel c, and the ends of the chain being crossed are connected
respectively to the tiller-arms b, b¹.
"
By this arrangement it will be seen that when the tiller is amidships, as shewn
in Figure 1, the side of the eccentric chain wheel having the maximum radius will
pull upon the chain and when the tiller is being moved to the "hard over
position shewn in Figure 2, (and whether to port or to starboard) the further it is
moved the shorter becomes the radius of the eccentric acting on the chain, thereby
obtaining similar results to those obtained by the gear constructed according to my
said former Patent, viz., relatively quick motion with small power when little work
has to be done as when the rudder is about in the mid position, as shewn in Figure 1,
and slower motion with greater power when the resistance has increased as when the
rudder and tiller are in the "hard over" position as in Figure 2.
In the drawing I have shewn my eccentric chain wheel as being circular in form.
In practice, however, it has to be made slightly elliptical in order that the chain
shall be kept taut in all positions.
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 :-
Steering gear for ships or boats consisting of a tiller fixed to the rudder head, a
chain wheel set eccentrically upon a driving shaft and a chain passing round the
eccentric the ends of the chain being connected respectively to arms on the tiller in
the manner and for the purpose, substantially as described.
Dated the 24th day of March 1896
G. F. REDFERN & Co.,
4, South Street, Finsbury, London, Agents for the Applicant.