IMPROVEMENTS IN STEERING APPARATUS FOR VESSELS
Year: 1883

page_text: LETTERS PATENT to John Donaldson, of the firm of John I. Thornycroft
and Co of Church Wharf, Chiswick, in the County of Middlesex, Steain
Yacht and Launch Builders for an Invention of IMPROVEMENTS IN STEERING
APPARATUS FOR VESSELS
"
PROVISIONAL SPECIFICATION left by the said John Donaldson at the
Office of the Commissioners of Patents on the 27th January 1883.
JOHN DONALDSON, of the firm of John I Thornycroft and Co, of Church Wharf,
Chiswick, in the County of Middlesex, Steam Yacht and Launch Builders,
IMPROVEMENTS IN STEERING APPARATUS FOR VESSELS'
"
My invention is designed to produce a light and efficient arrangement of
steering apparatus whereby a rudder may be worked at will either by hand or
through a motor actuated by suitable actuating fluid such as steam.
In suitable bearings in a bracket-like frame (which may conveniently be bolted
to a bulkhead or conning tower) I arrange two shafts parallel to each other.
One I will call the steering wheel shaft, the other the chain wheel shaft. The
steering wheel shaft is able to move endwise to a limited extent. It passes
through a sleeve formed with an external screw thread fitting a correspondingly
threaded hole in the frame. By a feather or feathers this sleeve is made to rotate
with the shaft, and through an arm and a vertical spindle actuates an indicator
finger that shews the position of the rudder
On the chain wheel shaft is keyed a worm wheel in gear with a worm on the
crank shaft of the engine, whose cylinders are arranged at the respective sides of
the frame.
The chain wheel is normally free to turn on its shaft, and has formed with it a
spur wheel and part of a clutch. The other part of the clutch is moveablo
lengthwise of the shaft but cannot rotate independently of it.
The steering wheel shaft carries an arm and two spur wheels; the arm operates
the moveable part of the clutch on the chain wheel shaft when the steering wheel
shaft is moved endwise.

page_text: One of the spur wheels is fast on the shaft and when the clutch is out of gear
this spur wheel gears with that of the chain wheel. When this obtains the second
spur wheel on the steering wheel shaft does not rotate with that shaft.
But it is always in gear with a nut wheel situate on a screwed part of the chain
wheel shaft and which is formed with an annular groove whereby through suitable
levers and rods the distributing valves of the engine are controlled.
For steering by hand the longitudinal position of the steering wheel shaft is
such that the moveable part of the clutch on the chain wheel shaft is out of gear
with the part carried by the chain wheel and one of the spur wheels that is fast
on the steering wheel shaft is in gear with the spur wheel of the chain wheel.
In this position if the steering wheel shaft be turned it will rotate the chain
wheel so as to actuate the rudder but will not turn the nut wheel already
mentioned.
To operate the rudder through the engine, the steering wheel shaft is moved
into such a longitudinal position that through the clutch the chain wheel is made
temporarily fast to its shaft so that it must rotate therewith, and its spur wheel
is then out of gear with that on the steering wheel shaft. But by a key or
feather the secured spur wheel on the steering wheel shaft is obliged to rotate with
its shaft.
In this position by turning the steering wheel the nut wheel is turned so as to
operate the valves of the engine, and as the engine answers to such movement of
the valve it not only rotates the chain wheel so as to operate the rudder, but
also tends (through the screwed portion of the chain wheel shaft) to return the
nut wheel.
The arrangement of differential gear and of the valves and ports or passages for
the actuating fluid is such that the engines may be readily started stopped and
reversed as may be required.
I. provide a pawl arrangement whereby the steering wheel shaft can be secured
in the end wise position for hand steering or for steering by power as required. In
some cases I modify the construction of the frame so that the apparatus can be
bolted to the deck of a vessel.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said John Donaldson in the Great Seal Patent Office on the 27th July
1883.
JOHN DONALDSON of the firm of John I. Thornycroft & Co: of Church Wharf
Chiswick in the County of Middlesex, Steam Yacht & Launch Builders
IMPROVEMENTS IN STEERING APPARATUS FOR VESSELS
My invention is designed to produce a light and efficient arrangement of
steering apparatus whereby a rudder (or rudders) may be worked at will either by
hand or through a motor actuated by suitable actuating fluid such as steam.
In suitable bearings in a bracket-like frame (which may conveniently be bolted
to a bulkhead or conning tower) I arrange two shafts parallel to each other. One
I will call the steering-wheel shaft; the other the chain wheel shaft. The steering
wheel shaft is able to move endwise to a limited extent. It passes through a
sleeve formed with an external screw thread fitting a correspondingly threaded
hole in the frame. By a feather or feathers this sleeve is made to rotate with the
shaft, and through an arm and a vertical spindle actuates an indicator finger that
shews the position of the rudder or of the tiller according as it is arranged. The
primary object of the sleeve is to limit the number of revolutions in either direction
of the steering wheel and so to prevent undue straining of the tiller, rudder, and
their connections. The sleeve has at each end a projection that comes in contact
with a stop fixed to the frame through which the screwed sleeve extends.
prevents jamming between either of the collars of the screwed sleeve and the frame
or the screw thread.
This
On the chain-wheel shaft is keyed a worm-wheel in gear with a worm on the
crank shaft of the engine, whose cylinders are arranged at the respective sides of
the frame. The chain wheel is normally free to turn on its shaft, and has formed with
it a spur wheel and part of a clutch. The other part of the clutch is moveable
lengthwise of the shaft but cannot rotate independently of it. The steering wheel
shaft carries an arm and two spur wheels. The arm operates the moveable part of
the clutch on the chain wheel shaft when the steering wheel shaft is moved end-
wise; thus it couples the chain wheel on the shaft with the worm wheel, or
uncouples it.
One of the spur wheels is fast on the steering-wheel shaft and when the clutch is
out of gear this spur wheel gears with that of the chain wheel. When this obtains the
second spur wheel on the steering wheel shaft does not rotate with that shaft.
But it is always in gear with a nut wheel situate on a screwed part of the chain
wheel shaft and which is formed with an annular groove whereby through a
suitable lever and rods the distributing valves of the engine are controlled.
For steering by hand the longitudinal position of the steering wheel shaft is
such that the moveable part of the clutch on the chain wheel shaft is out of gear
with the part carried by the chain wheel and one of the spur wheels that is fast on
the steering wheel shaft is in gear with the spur wheel of the chain wheel.
In this position if the steering wheel shaft be turned it will rotate the chain
wheel so as to actuate the rudder but will not turn the nut wheel already
mentioned.
To operate the rudder through the engine, the steering wheel shaft is moved
into such a longitudinal position that through the clutch the chain wheel is made
temporarily fast to its shaft, so that it must rotate therewith, and its spur wheel is
then out of gear with that on the steering wheel shaft. But by a key or feather
the second spur wheel on the steering wheel shaft is obliged to rotate with its
shaft, when the shaft is in the position just referred to..

page_text: In this position by turning the steering wheel the nut wheel is turned so as to
operate the valves of the engine, and as the engine answers to such movement of
the valve it not only rotates the chain wheel so as to operate the rudder, but also
tends (through the screwed portion of the chain wheel shaft) to return the nut
wheel.
The arrangement of differential gear and of the valves and ports or passages for
the actuating fluid is such that the engines may be readily started, stopped and
reversed as may be required
I provide a pawl arrangement whereby the steering wheel shaft can be secured
in the endwise position for hand steering or for steering by power as required.
In some cases I modify the construction of the frame so that the apparatus can be
Fig 1 is an end elevation of my improved steering apparatus, Fig 2 is a longi-
tudinal vertical section of the same, and Fig 3 is a plan partly in section, a is a
bracket or frame fixed to a conning tower b and carrying in suitable bearings as
shewn two shafts c and d parallel to each other, of which c is the steering wheel
shaft and d the chain wheel shaft. The steering wheel shaft c passes through a
sleeve e formed with an external screw thread fitting into a correspondingly screwed
bearing in the frame a. By a feather or feathers this sleeve is made to rotate with
the shaft c and as the said shaft is turned to the right or left the screwed sleeve
moves endwise and actuates an indicator finger f through a vertical spindle f' and
arm f taking into a grooved disc f111 carried by the screwed sleeve e whereby the
position of the rudder or tiller is shewn. On the chain wheel shaft d is keyed a
worm wheel g in gear with a worm g¹ on the crank shaft h of the engine whose
The chain wheel k
cylinders ii are arranged at the respective sides of the frame.
is normally free to turn on its shaft d and has formed with it a spur wheel / and
part of a clutch l¹. The other part of the clutch is moveable lengthwise of the
shaft but cannot rotate independently of it. The steering wheel shaft c carries an
arm m, in the boss m³ of which it is free to rotate but without end play, the said
The arm m is
boss being confined between the collar m" and the fixed wheel n
bifurcated, its fork takes into the groove of the moveable part of the clutch
so that any end motion of the shaft c must be imparted to the clutch piece 71. o is
a locking spindle swivelled at one end in the arm m but without end play therein;
the other end of this spindle passes through a boss in the frame and is furnished
with a collar o¹, also with a stud or detent o' that is capable of being passed through
a key-way or channel cut in the hole in the frame through which the spindle passes
so that when the stud is passed through the boss to either side of it, and the
spindle o then turned say one quarter of a turn, by means of a hand lever o*
outside the frame, the spindle o, the clutch piece and the steering wheel shaft
are locked in the required position. The collar o' on the spindle o limits its travel
and that of the shaft c towards the left of Fig 2. p is a spur wheel having a
somewhat elongated hollow boss by means of which it is fixed in the end frame a
so as to rotate freely; this hollow boss forms the end bearing of the steering wheel
shaft c and has at its inner end suitable key-ways cut to receive short feathers
formed on the shaft c so that when this shaft is thrust towards the wheel p the
feathers take into the boss and cause the wheel p to rotate with the shaft-when
the shaft is withdrawn it can rotate independently of the wheel leaving the latter
at rest. The wheel p is always in gear with a wheel q which has its boss screwed
internally and fitted so as to work freely on the screwed end of the chain wheel
shaft d; the boss of the wheel q is elongated and is formed with a fork-groove q¹
similar to that in the clutch piece 7"-stop pieces are provided both on the ends of
the boss of the wheel q and at both ends of the screw of shaft & so as to prevent
the thread of the nut wheel 7 jamming at either end of its travel. The same plan
is adopted in the case of the screwed sleeve e before mentioned, ex e* being stop

page_text: pieces on the sleeve and a* a* stop pieces on the frame. r is a forked lever jointed
to a standard fixed to the frame a, this forked lever takes into the groove q¹ in
the boss of wheel q and actuates the reversing distributing valve by means of a
rod 8.
t is the valve for admitting, stopping and reversing the steam.
The operation of the apparatus is as follows:-
In the drawings it is shewn in gear for steering by the aid of the engine and the
parts are in their mid positions. The steering wheel shaft is thrust as far as
possible to the right (in Fig 2); its feathers are in gear with the wheel p, the
fixed wheel n is out of gear with the spur-wheel and the clutch piece is in gear
with ; the index f also shews that the rudder or tiller is in a line with the keel
of the vessel (see Fig 3)
Steam being admitted to the valve chest x none can enter the steam chests of
the cylinders ii as the valve t on the end of the rod a completely covers the steam
ports and consequently all is at rest; but the moment the steering wheel is turned
either way the wheel p turns the wheel q which consequently travels longitudinally
on the screwed end of the chain wheel shaft & and by means of the lever r actuates
the rod 8 and the valve t admitting steam to the steam chests of the cylinders that
drive the crank shaft, either one way or the other, that is to say, either directly
through the steam pipe proper into the steam chest of each cylinder in which case
the steam enters the steam ports of the cylinders at the ends of the slide valves;
or through what is usually the exhaust pipe into the middle of the slide valves in
which case the steam enters the steam ports from the middle of the valve thus
causing the engines to work to the right or left according to the position of the
valve t, and so rotating the chain wheel shaft d one way or the other as the case
may be through the medium of the worm g' and the worm wheel g.
As soon as the chain wheel shaft d begins to rotate the action of the screw on
its end tends to restore the nut-wheel q, the lever and the valve t to their central
positions (shewn in Fig 2) and thus to prevent any further motion until the
steering wheel shaft c is again rotated either way, when motion will again
cominence, continue as long as c is rotated, and then cease as explained above on
account of the neutralizing motion of the screw on the end of the chain wheel
shaft d. To steer by hand it is only necessary to close the valve t, turn the locking
spindle o to the position shewn in Fig 2 so that the stud or detent can pass through
the channel in the frame-boss, draw back the shaft c until the collar o' comes in
contact with the frame-boss, give the spindle o a quarter turn and thereupon the
shaft c will be out of gear with the wheel p-the wheel n will be in gear with the
spur wheel the clutch piece will be withdrawn from and all will now be in
position to drive the chain wheel, which is free on the shaft d without the inter-
vention of the engine and thus the steering will be effected by hand.
It will be observed that the steering wheel can only be turned to a limited extent
as the stops on either end of the screwed sleeve e come into contact with the stops
on the frame and so bring the shaft c to a dead lock without throwing any jamming
strain on the thread or collars. It will be seen that the apparatus is enclosed in a
casing comprising sides w w¹ hinged respectively at w₁ and will and also a top will
which is capable of being lifted off. The apparatus is thus protected from dirt
and injury, but at the same time is readily accessible for examination or other
purposes by simply removing the top and opening the side doors.
Having described the nature of the said invention and in what manner the same
is to be performed I would have it understood that what I consider to be novel
and original and therefore claim as the invention secured to me under the Letters
Patent first hereinabove in part recited is :-
1. The improved steering apparatus for vessels constructed arranged and
operating as hereinabove described with reference to the drawings.
2. In a steering apparatus for vessels, limiting the rotations of the steering
wheel by the use of a screwed sleeve in the manner hereinabove described with
reference to the drawings.

page_text: 3. In a steering apparatus for vessels the use in conjunction with the steering
wheel shaft and the sleeve thereon of an indicator arranged and operating substan-
tially as described for indicating the position of the rudder or tiller as above set
forth.
4. In steering apparatus for vessels the arrangement substantially as described
for effecting at will by endwise movement of the steering wheel shaft the placing
of the parts in gear for steering through a motor and out of gear for hand steering
or in gear for hand steering and out of gear with the motor as above set forth.
5. In a steering apparatus for vessels such as referred to in claim 4 the arrange-
ment described for locking the parts in position to steer by hand direct or through
the motor as above set forth.
6. In a steering apparatus for vessels wherein two parallel shafts, namely, a
steering wheel shaft c and a chain wheel shaft d in gear with the main shaft of a
motor, are employed, the use of the combined arrangement hereinabove described
with reference to the drawings for producing differential motion communicated to
the reversing distributing valve as above set forth.
In Witness whereof I the said John Donaldson have hereunto set my hand
and seal this twenty sixth day of July in the year of our Lord one thousand
Eight hundred and Eighty three
JOHN DONALDSON. (L.S.)