IMPROVEMENTS IN CONNECTED WITH STEERING ENGINES
Year: 1882

page_text: LETTERS PATENT to Thomas Davison, of Glasgow, in the County of Lanark,
North Britain, Engineer, for an Invention of "IMPROVEMENTS IN
CONNECTED WITH STEERING ENGINES
"
AND
PROVISIONAL SPECIFICATION left by the said Thomas Davison at the Office
of the Commissioners of Patents on the 11th September 1882.
THOMAS DAVISON, of Glasgow, in the County of Lanark, North Britain,
Engineer, "IMPROVEMENTS IN AND CONNECTED WITH STEERING ENGINES"
This Invention has for its object to simplify, cheapen, and otherwise improve the
construction of steering engines and parts connected therewith.
In carrying out the Invention a horizontal screw shaft is arranged to act directly
on the tiller, there being an internally screwed sleeve or nut on the screw shaft and
a plain sleeve on the tiller, the sleeve on the tiller moving to a limited extent along
the tiller to accomodate itself to the various positions of the sleeve on the screw
shaft, and the two sleeves being jointed together by a vertical pin which can be
lifted out when it is wished to disconnect the steering engine from the tiller. The
tiller is in two parts, the part having the sleeve on it being jointed at or near the
rudder stock and passing between jaws formed on the other part of the tiller which
latter part is rigidly fixed to the rudder head or stock. Blocks of rubber are fixed
to the inner sides of the jaws for the purpose of forming a slightly yielding
connection between the rudder and the machinery which will tend to diminish the
effects of concussive action.
The screw shaft is formed with or is fixed to a crank shaft constituting an extension
of it beyond the screwed part; or the screwed shaft may be geared to a crank
shaft. The crank shaft is arranged in connection with two small steam cylinders
by which it is driven, the distribution valves of these cylinders being piston valves
worked by eccentrics on the crank shaft and the direction of rotation being
determined by a third or controlling valve which is like an ordinary slide valve and
which according to its position directs the steam either to the ends or middles of
the chambers in which the piston valves work. The third or controlling valve is

page_text: worked by a lever acted on by a controlling rod which has both a longitudinal and
a turning motion, and which has one end in a plain bearing in the framing whilst
the other end enters a tubular shaft in which it can move longitudinally and with
which it is made to turn by means of a groove and feather. The tubular shaft is
connected to the steering wheel either directly or through suitable shafting which
is by preference of the kind hereinafter described. The controlling rod has part of
its length screwed and working in an internally screwed block and when the rod
is turned in consequence of the steering wheel being turned the screw action in
the block makes the rod move endways and shift the lever of the controlling
valve. A screwed shaft held in bearings so as to be parallel to the controlling rod
works in an internal screw in the same block as that rod, and is geared by bevil
wheels to the crank shaft of the engine; and when the engines turn in either
direction in consequence of the movement of the controlling valve produced by
turning the steering wheel they by turning the screw shaft which is parallel to the
controlling rod move the block and through it make the controlling rod move
endways so as to restore the controlling valve to its neutral position.
Some parts of the mechanism herein before described may be modified to suit
different cases. Instead of the engine being directly connected to the tiller as
described the sleeve on the screwed shaft may be connected to the tiller or an
equivalent part by chains or links. There may be screwed extensions of the crank
shaft on both sides of the engines with nuts or internally screwed sleeves on each
extension and connected to the rudder by chains or otherwise. Or a tubular shaft
formed or fitted with eccentrics may be substituted for the crank shaft and may
be internally screwed or fitted with one or more internally screwed bushes to act
on a screwed shaft passing through it, this screwed shaft being prevented from
turning by a groove and a fixed key and having the rudder chains connected to its
opposite ends.
The
When the steering wheel is at any distance from the engine it is connected to
the engines according to this Invention by light shafting made of metal tubes, any
parts not in line being connected by universal joints or by bevil gearing.
several lengths of tubing are connected to each other by short lengths of solid brass
or other suitable metal fixed or jointed into the ends of the tubes, but with their
middle parts uncovered by the tube ends and serving as journals to work in the
bearings which carry the shafting. In this way journals of smaller diameter than
the outsides of the tubes and having less friction in consequence are obtained
in a simple manner combined with a convenient mode of connecting the tube
lengths.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said Thomas Davison in the Great Seal Patent Office on the
9th March 1883.
THOMAS DAVISON, of Glasgow, in the County of Lanark, North Britain,
Engineer "IMPROVEMENTS IN AND CONNECTED WITH STEERING ENGINES
"
My said Invention has for its object to simplify, cheapen, and otherwise improve
the construction of steering engines and parts connected therewith.
In carrying out my Invention a horizontal screw shaft is arranged to act directly
on the tiller; and the tiller is made in two parts, the parts connected to the screw
shaft being jointed at or near the rudder stock and passing between jaws formed
on the other part of the tiller which latter part is rigidly fixed to the rudder head
or stock, Blocks of rubber are fixed to the inner sides of the jaws for the purpose
of forming a slightly yielding connection between the rudder and the machinery,
which arrangement will tend to diminish the effects of concussive action.
The screw shaft is formed with or is fixed to a crank shaft constituting an
extension of it beyond the screwed part. The crank shaft is arranged in connection
with two small steam cylinders by which it is driven, the distribution valves of
these cylinders being piston valves worked by eccentrics on the crank shaft, and
the direction of rotation being determined by a third or controlling valve, which
is like an ordinary slide valve, and which according to its position directs the
steam either to the ends or middles of the chambers in which the piston valves
work. The third or controlling valve is worked by a lever acted on by a controlling
rod which has both a longitudinal and a turning motion and which has one end in
a plain bearing in the framing whilst the other end enters a tubular shaft in which
it can move longitudinal and with which it is made to turn by means of a groove
and feather. The tubular shaft is connected to the steering wheel either directly
or through suitable shafting which is by preference of the kind hereinafter
described. The controlling rod has part of its length screwed and working in an
internally screwed block, and when the roi is turned in consequence of the steering
wheel being turned the screw action in the block makes the rod move endways and
shift the lever of the controlling valve. The screwed block is connected by a
screwed shaft and bevil wheels to the crank shaft in such a manner that the
action of the engines always restores or tends to restore the controlling valve to its
neutral position.
Some parts of the mechanism herein before described may be modified to suit
different cases.
Instead of the engine being directly connected to the tiller as
described the connection may be by chains or links. Or a tubular shaft formed
or fitted with eccentrics may be substituted for the crank shaft and may be
internally screwed or fitted with one or more internally screwed bushes to act on a
screwed shaft passing through it, this screwed shaft being prevented from turning
by a groove and a fixed key and having the rudder chains connected to its opposite
ends.
And in order that my said Invention and the manner of performing the same
may be properly understood I hereunto append four sheets of explanatory drawings.
to be hereinafter referred to and representing examples of my improved steering
machinery.
Figure 1 on sheet 1 of the accompanying drawings is a plan of one modifica-
tion of my improved steering machinery and figures, 2, and 3, are side and back
elevations. Figure 4 on sheet 2 is an enlarged sectional plan of the engines and
figures, 5, and 6, are corresponding longitudinal and transverse vertical sections,

page_text: Figures, 7, to 15, on sheet 3, are enlarged views of various details; and figure, 16,
on sheet, 4, is a plan of a second modification of the engines. In these drawings
the same reference numerals are used to mark the same or like parts wherever they
repeated.
In the arrangement shown in figures 1, 2, and 3, the rudder stock, 21, has fixed
on it a short arm or lever, 22, which combined with a longer arm, 23, forms the
tiller, and which is shown separately in plan in figure, 13, the longer arm, 23, being
shown in figure, 12. The arm, 23, is centered on the upper round part of a pin or
bolt, 24, the lower square part of which passes through a square hole in the shorter
tiller arm, 22, being fitted to the square hole so as to allow of a little play vertically
and in a radial direction to enable the longer tiller arm, 23, to accomodate itself to
slight differences of level between the rudder stock and parts acting on the tiller
due to wear of the rudder pintles. The shorter arm, 22, is made with jaws, 25,
between which the longer arm 23 lies, and blocks, 26, of rubber are fixed to the
inner sides of the jaws to form a slightly yielding connection between the rudder
and the machinery so as to diminish the effect of concussive action. Eye bolts 27
are screwed to the jaws, 25, for the attachment of chains in the event of their
being required, and the points of these eye bolts penetrate into the rubber blocks, 26,
and serve to keep them in place. The outer part of the longer tiller arm, 23, is
made cylindrical to receive a sleeve, 28, formed in a piece shown separately and
enlarged in figures 7, 8, and 9, and which serves to connect the tiller to a piece
shown separately and enlarged in figures, 10, and 11, the latter piece being made
with an internally screwed sleeve, 29, to work on the screw shaft, 30. The two
sleeve pieces are formed with bored bosses 31, 32, to receive a connecting pin, 33,
and the bosses are formed with flanges or discs, 34, 35, which bear upon each other
when the parts are connected, and of which one is formed with a grooved flange, 36,
to overlap the edge of the other to prevent the parts getting out of their proper
positions relatively to each other when introducing or withdrawing the pin, 33,
The combination of the sleeve pieces, 28, 29, with the pin, 33, forms a universal
joint connection between the screw shaft, 30, and the tiller arm, 23, and adapts
itself to the different angular positions of the tiller, the sleeve, 28, sliding inwards
or outwards along the tiller arm, 23, when the sleeve, 29, is moved along the screw
shaft, 30, by the rotation of the latter. And it is an important advantage of the
arrangement that the tiller can be disconnected with great facility by lifting out
the pin 33.
The screw shaft, 30, is formed in one piece with or is coupled to a crank
shaft, 37, arranged to be driven by two small steam cylinders, 38, having improved
valve details which will be best understood from the enlarged views, figures, 4, 5,
and 6. Piston valves, 39, worked by eccentrics, 40, on the crank shaft, 37, are
used for distributing the steam to and from the opposite ends of the cylinders, and
a third or controlling valve, 41, leads the steam to and from the distribution
valves, 39. This controlling valve, 41, which is a common slide valve is in a
casing, 42, formed beneath the two chambers of the distribution valves, 39, and it
works up against a port face having a middle or exhaust port, 43, communicating
with the exhaust pipe, and towards each end ports, 44, 45, leading respectively to
the spaces at the ends of the piston valves, 39, and to the middle spaces between
each pair of those valves. The parts are contrived so that the spaces and passages
which have to be filled and emptied of steam at each change of action of the
engines may be as small as possible. When the controlling valve, 41, is in its
middle position the steam has no access to the cylinders and on being moved
towards one end, it admits the steam so as to drive the engine in one direction,
whilst if it is moved towards the other end the steam will drive the engine in the
opposite direction as is well understood.
The controlling valve, 41, is moved by a lever, 46, the outer end of which is
forked and engages with a block fitted between collars on a controlling rod or
shaft, 47. This controlling shaft, 47, can turn and also move on end, one end being
in a plain bearing in the framing and the other in a short tubular shaft, 48, with

page_text: which latter it is made to turn by a groove and feather whilst it can move on end
in it. A screw thread, 49, is formed on a part of the controlling shaft, 47, to work
in an internally screwed block, 50, and this block receives a longitudinal motion
from the crank shaft, 37, through a pair of bevil wheels, 51, and a screw shaft, 52,
The tubular shaft or piece, 48, is connected either directly or through shafting, 53,
and bevil gearing, 54, as shown in figures, 2, and 3, to the steering wheel 55; and
whenever this steering wheel is moved the controlling shaft, 47, is turned and by
the action of its screw thread, 49, in the block, 50, it becomes moved on end so as
to shift the lever, 46, of the controlling valve, 41. In response to the movement
of the controlling valve the engine operates and through the screw shaft 30, effects
the desired movement of the rudder, and at the same time the bevil wheels, 51,
and screw shaft, 52, move the block, 50, and through it shift the controlling
shaft, 47, on end in the opposite direction to the movement which it had in starting
the engine, and the controlling valve, 41, is thereby restored to its middle or
neutral position. The range of movement of the engines is determined by stop
collars upon the screwed part, 49, of the controlling rod or shaft, 47, these collars
limiting the extent of movement of the block, 50, along the shaft.
The steering wheel, 55, is in figures 2 and 3, represented as carried by a
convenient hollow pedestal, 56, having at its top a spherical casing, 57, to contain
the bevil wheels gearing the horizontal shaft of the steering wheel, 55, to the
vertical shaft, 53, passing down through the pedestal. A pointer, 58, to indicate the
position of the rudder is fitted to the top of the spherical casing, 57, and the
mechanism which I have devised for actuating it is shown in figure, 14, which is
an enlarged plan of the spherical casing, 57, with its cover removed but with the
external pointer, 58, indicated by dotted lines. This pointer is on a vertical
spindle 59, having fixed on its bottom end a disc, 60, made with a radial slot at
right angles to the pointer, 58, and in contact with the underside of the disc, 60,
there is the flat top of a block, 61, which is fitted with a pin projecting up into
the radial slot, and which is made like a nut with an internal screw thread to
work on a screw thread formed on the shaft, 62, of the steering wheel, 55. The
screw thread of the shaft, 62, is made of a suitable pitch so that the angular
movement imparted by the pin in the nut block, 61, to the disc, 60, and to the
pointer, 58, is identical with that imparted by the main screw shaft, 30, to the
tiller, 23, and the position of the pointer, 58, must therefore always coincide with
that of the rudder. The nut block, 61, is prevented from turning by its flat top
being in contact with the underside of the disc, 60.
In the modification of my improved steering engine shown in figure, 16,
eccentrics, 64, are substituted for the cranks, so as to allow of the shaft, 65, being
tubular; and this tubular shaft is formed with an internal screw thread or is
fitted with one or more internally screwed bushes in which works a screw shaft, 66.
This screw shaft, 66, is prevented from turning by a key, 67, fixed in a bearing
and which projects into a longitudinal groove formed across the screw threads of
the shaft. Chains or links are connected to the ends of the screw shaft, 66, to
transmit to the rudder the motion which the rotation of the engine shaft, 65,
imparts to it.
When the steering wheel (55) is at any distance from the engine it is connected
thereto according to my Invention by light shafting made of metal tubes, any parts
not in line being connected by universal joints or by bevil gearing. The several
lengths of tubing are connected to each other as shown in figure, 15, sheet, 3, by
in each case a short length, 68, of solid brass or other suitable metal fixed or
jointed into the ends, 69, of the tubes, but with the middle part uncovered by the
tube ends and serving as a journal to work in the bearing, 70, which carries the
shafting. In this way journals of smaller diameter than the outsides of the tubes,
and having less friction in consequence, are obtained in a simple manner combined
with a convenient mode of connecting the tube lengths. In figure, 15, the
bearing, 70, is shown as attached to one, 71, of the ship's beams.
Having thus particularly described my said Invention and the manner of

page_text: performing the same I have to state that I do not restrict myself to the precise
details herein described or delineated but that what I believe to be novel and
original and claim as the Invention secured to me by and in terms of the
herein before in part recited Letters Patent is :-
1. The arranging or combining together of the parts of steering engines
substantially in the improved manner hereinbefore described with reference to
figures 1 to 13, of the accompanying drawings.
2. The constructing of the tiller in two parts having a slightly yielding connection
substantially as and for the purposes hereinbefore described.
3. The combination of the sleeve pieces (28, 29) and movable pin (33) for
connecting the screw shaft (30) to the tiller arm (23) the parts being constructed
and arranged substantially as hereinbefore described.
4. The combination of a screw shaft driven directly by a pair of steam
cylinders arranged at one end of it, with the tiller, the screw shaft and tiller being
directly connected by a pair of sleeve pieces and movable pin as herein before
described.
5. The arranging and combining together of the distribution and controlling
valves and the valve chambers and passages in the improved manner shown in the
accompanying drawings and as hereinbefore described."
6. The combination of the controlling valve lever (46) the controlling rod or
shaft (47) the block (50) and the screw shaft (52) which is turned by the engines
and shifts the block, the parts being arranged and operating as hereinbefore
described.
7. The mechanism for actuating the position indicator near the steering wheel
and operating like the parts acting directly on the tiller, as herein before described
with reference to figure, 14, of the accompanying drawings.
8. The making of the shafting for transmitting the motion from a steering
wheel to the engines of tube lengths connected by solid pieces serving also as
journals for the bearings which carry the shafting substantially as hereinbefore
described.
9. The making of the steering engine with a tubular shaft having eccentrics on
it instead of cranks and having a screw shaft passing through it as herein before
described with reference to figure, 16, of the accompanying drawings.
In Witness whereof 1, the said Thomas Davison, have hereunto set my hand
and seal this seventh day of March in the year of our Lord One thousand
eight hundred and eighty-three.
THO. DAVISON (L.S.)