Improvements in Steering Gear for Ships and Boats.
Year: 1889

page_text: Date of Application. 19th July, 1889
Complete Specification Left, 18th Apr., 1890-Accepted, 24th May. 1890
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:-
My improvements relate to steering gear for ships and boats, and have for their
object to proportion or distribute the available operating power, according to the work
to be done, or the resistance to be overcome.
On the rudder head (or on a post supplemental to the rudder head but connected
thereto by links and cross-heads or other means) I fix a tiller which carries on the
outer or free end a toothed rack formed or curved to gear with teeth on an eccentric
or can shaped pinion, which pinion is carried on a spindle and so placed that, when
the tiller is amidships the side of the pinion of longest or largest radius is in gear
with and acting upon the tiller, and that when the tiller is "hard over to port
"starboard" the side of the pinion of shortest radius is in gear with and acting upon
the tiller.
or
By this means I effect two desirable results, for when there is little work to be-
done, that is when the portion of the pinion of longer radius is acting, it moves the
tiller at a relatively quick speed, and when great resistance has to be overcome then
the portion of the pinion of shorter radius comes into action and operates more
powerfully and with a slower motion of the tiller.
Dated the 19th day of July 1889
G. F. REDFERN & Co.,
4, South Street, Finsbury, London, Agents for the Applicant.
COMPLETE 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 and in what manner the same is to be performed to be particularly
described and ascertained in and by the following statement:—
My improvements relate to steering gear for ships and boats, and have for their
object to proportion or distribute the available operating power, according to the
work to be done, or the resistance to be overcome.
On the rudder head (or on a post supplemental to the rudder head but connected
thereto by links and cross-heads or other means) I fix a tiller which carries on the
outer or free end a toothed rack formed or curved to gear with teeth on an eccentric
or cam shaped pinion, which pinion is carried on a spindle and so placed that
when the tiller is amidships the side of the pinion of longest or largest radius is in
gear with and acting upon the tiller, and that when the tiller is "hard over to port”
"hard over to starboard the side of the pinion of shortest radius is in
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with and acting upon the tiller.
gear
To enable my invention to be fully understood I will describe the same with
reference to the accompanying drawings, in which
Figure 1 is an elevation, and
Figure 2 a plan of the gear when in mid position; and
Figure 3 is a plan when the tiller is "hard over."
"
Similar letters of reference indicate corresponding parts in the several figures.
a indicates the rudder-post and & the tiller fixed thereon and having teeth formed.

page_text: or carried on the outer end and constituting a rack; and c is the pinion engaging
with the rack-teeth. This pinion is fixed eccentrically upon the shaft d so as to make
a maximum and minimum radius, the teeth of the pinion on the side having the longer
radius being engaged with those teeth on the tiller nearest the rudder-post, as shown
in Figure 2 where the tiller bis represented in mid-position. I make the number
of teeth on the tiller & to correspond with the number of teeth on the pinion c, so
that when the said pinion is rotated to bring the tiller b into the "hard over'
position see Figure 3-the teeth of the pinion on the side having the shortest
radius are engaged with those teeth on the tiller furthest from the rudder-post.
By this arrangement, at the same time that I increase the leverage or acting length
of the tiller from the mid-position I increase also the leverage of the pinion c, owing
to its being eccentrically fixed upon the shaft d.
By the means herein before described I effect two very desirable results, that is to
say,
I obtain relatively quick motion with small power whon little work has to be
done, namely, when the rudder is about in the mid-position as in Figure 2; and slow
motion with greater power when the resistance has greatly increased, namely,
when the rudder and tiller are in the "hard over" position as in Figure 3.
When the available space around the rudder-post is small I use rods as e, e and a
cross-head, shown by dotted lines, to connect my improved tiller with the rudder-
post, which in such cases is, as shown, at a', a being then an auxiliary post used for
steadying and pivotting the tiller.
Although I have described the pinion as being circular it is to be understood that
it may be of elliptical or other suitable shape, the curve of the line of the teeth of the
tiller being correspondingly varied to engage therewith.
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.) Steering gear for ships or boats comprising a tiller affixed to the rudder-head
and formed with a curved toothed rack adapted to engage with a pinion set eccentrically
upon a driving shaft, whereby the available operating power is applied more effectively
as the resistance to be overcome increases.
(2.) Steering gear for ships or boats comprising a tiller affixed to the rudder-head
and formed with a curved toothed rack adapted to engage an elliptical or cam-shaped
gear set upon a driving shaft, whereby as the resistance to be overcome increases the
available operating power is applied more effectively, substantially as described.
Dated the 18th
Anil 1800
G. F. REDFERN & Co.,
4, South Street, Finsbury, London, Agents for the Applicant.