IMPROVEMENTS IN THE PROPULSION AND STEERING OF STEAM SHIPS OR VESSELS, AND IN THE CONSTRUCTION OF PROPELLERS AND MECHANISM THEREFOR, PART OF WHICH IMPROVEMENTS IS APPLICABLE TO WATER WHEEL MOTORS
Year: 1880

page_text: PROVISIONAL SPECIFICATION left, by John Lorimer Corbett and William
Lochhead at the Office of the Commissioners of Patents on the 17th January
1880.
JOHN LORIMER CORBETT, and WILLIAM LOCHHEAD, both of Glasgow, in the
County of Lanark, North Britain. "IMPROVEMENTS IN THE PROPULSION AND
STEERING OF STEAM SHIPS OR VESSELS, AND IN THE CONSTRUCTION OF PROPELLERS
AND MECHANISM THEREFOR, PART OF WHICH IMPROVEMENTS IS APPLICABLE TO
WATER WHEEL MOTORS."
This said Invention has reference to the propulsion and steering of steam ships
and vessels, and particularly to a new or improved construction of propeller
therefor, susceptible of various modifications; as also to particular arrangements
and combinations of its mechanism or parts and fittings (some of which are
applicable to water wheel motors), and which propeller and improvements con-
nected therewith, it is considered, will prove much more efficient in practice, and
convenient in many respects for effecting the said two purposes of propelling and
steering simultaneously, than any of the constructions of paddle wheels or screw
propellers heretofore used for effecting these joint purposes.
And the nature and novelty of the said new or improved construction of
propeller, under the first modification or general combination of parts, consist as
follows:-The central body part of the propeller consists of a large hollow close
cylinder, made preferably of sheet iron or steel, with a strong central eye or boss by
which it is secured on the lower end of its motive shaft ranged vertically in
suitable journal bearings with a water tight stuffing box below, so as to revolve as
a horizontal propeller wheel in the water, below the hull or bottom of the ship, or
the stern part, or it might be at the sides when two propellers are used, revolving
within segmental recesses formed in the hull of the ship on the inner segmental
non-propelling side of this central cylinder, which would be exposed on the outer
propelling side, where the new' or improved construction and arrangement of
propelling blades are projected out of the cylinder, so as to act on solid water, in
this case undisturbed by the motion of feathering the blades, as in some other forms
of propelling wheels. The propelling blades are fitted to slide with their edges
vertically and radially, out and in, through slots in the outer periphery of the said
central cylinder with the broad face of the blades protruding out, and acting
vertically and radially or circumferentially beyond the cylinder on the outer
propelling side, and drawn quite within it on the inner or other non-propelling
side.
'
These blades may be so mounted, to act as described, in any desired convenient
number, according to the size or diameter of the cylindrical wheel (as in most
other propelling wheels) as, say, from three to eight, as the preferable minimum
and maximum numbers, although a fewer or greater number might be used. It is
'

page_text: considered however that these blades would be better to lie slightly backward from
the true radial line at the outer acting end, and forwards at the inner end, so that
this end or guides on it might work in slides or guides past the front of the
vertical shaft within the hollow cylindrical centre when desired, or when this is
made small in diameter; while the acting face of cach blade in the propelling
direction is preferred to be made of a hollow segmental form or inwardly inclined
shape from the upper and lower advanced radial edges towards the centre to give
a better holding action on the water, and greater strength to the blade without
adding to its thickness or weight; also allowing convenient room at the back of
the advanced edges for securing strengthening slides and guide bars; or otherwise
these radial sliding propelling blades might be made corrugated vertically and
straight radially to slide in their segmental or corrugated grooves respectively,
which ever are adopted. Each blade of the whole set so fitted within the wheel
centre as it comes round to the proper propelling position would be reciprocated
outwards and inwards as it passed these positions, which are considered to be
about 60° in advance of and behind the radial line for the time being at right
angles to the true longitudinal line of propulsion, or the direction in which the
vessel is desired to move; this propeller and its blades thus protruding and acting
through about a third, or from a third to a fourth of its revolution.
This outward and inward reciprocation of the blades at the said times and
positions (as also the maintaining of them out while propelling on the one side of
the wheel centre or case, and within it on the other side while passing round on
the other or non propelling direction) is effected by one arrangement through an
arm or strong stud or studs projecting from the inner edges of each 'propelling
blade through a slot in the upper or both ends of the enclosing cylinder, so as to
work into a cam or cam groove on the under face of a cam disc mounted loose on
the propeller shaft close to the cylinder or concentric to it on the face of the recess
in the ship in which the propeller works, the cam having two concentric segments
or curves on or into which the studs work, corresponding to the outer and inner
position of the blades on the propelling and non-propelling arcs of their revolution
respectively, and gliding into each other in a gently inclined or curvilineal manner
at the immediate parts where the outward and inward motion of the blades takes
place. This cam is preferably enclosed within a close case, stationary or revolving
with the wheel, and the cam being held or turned by a large wheel on its boss by
a pinion or other equivalent gearing on the outer end of a light shaft passed.in
through a water-tight stuffing-box joint and bearing in the side of the ship, for the
purpose of turning the cam round to any position to propel and steer the ship in
any direction accordingly without stopping or reversing the revolving motion of
this propelling wheel or its motive gear and engine, but simply in accordance with
the side or arc; the blades are projected to propel as described all by a hand
steering wheel or motive power steering gear connected with the inner or upper
end of the said cam actuating shaft. An intermediate lever or levers might be
used between the stud of each blade, with another stud nearer the axes of the
levers working into or on the cam, so as to give a greater length of "throw"
motion to the blades with a smaller cam; and it will be evident also that a spring
or springs might be made to pull in or actuate the blades or their said levers in
the one direction, and the cam be made with only a single acting surface to press
them out or act in the reverse or other direction. In this construction of pro-
pelling horizontal wheel when arranged to work on its shaft in the centre line of
the keel as at the stern of the ship a second propeller of like construction could
be arranged or erected to work above the other on the lower end of a hollow
driving shaft mounted on the central shaft. of the lowest propeller; this hollow
shaft and its propeller being driven in the reverse direction to the other by
reversing gearing of its own from the same engine as the other propeller, or it
might be direct by a separate motive steam engine.
or
A somewhat different modification or construction and arrangement of these
improvements and propeller consists in projecting or pressing out the propelling

page_text: blades through slots formed in the lower face or end of the close cylinder, that is,
vertically or parallel to the line of its shaft (instead of through the circumference
as in the former modification), which in this case requires the cam or cam groove
surface formed on the circumference of the cam, so that the pins or anti-friction
rollers on the arms or rods and levers working the propeller blades will work
vertically as described. This modification of propeller with vertically acting
blades may be worked quite up into a recess in the bottom of the ship, either in
the centre line of the keel, or on each side of this when it is not desired to cut a.
recess out of the keel, and have the 'blades to project out as deep as the keel in
shallow water, and deeper when the depth of water will allow, or quite down
below it when out at sea.
One arrangement of fitting this new or improved propeller to the ship, and of
shaping the hull of the ship towards and from the propeller, to give less resistance
and greater propelling effect, consists in fitting one of the improved propellers on
each side of the keel in recesses about two thirds of the length of the ship from the
bow of the ship, or perhaps rather more than one third from the stern; and in
shaping and curving the rear parts and forward. parts of the hull respectively
converging into the recess containing the propelling wheel in a gradual manner, as
the stern and bow parts or "lines" of ships are, and in having the after part of
the hull of a much less cross-sectional displacement than the forward part, so that
the water displaced by the larger forward part and section would glide gently in
towards the front part of the propeller and its recess, and with the least possible
friction or resistance on the forward part of the rear smaller part of least cross-
section, which it is considered would lessen the friction and retarding action of the
displacement water at the stern of the ship, and so increase the speed.
It will be seen from the foregoing description of the construction of this improved
propeller in either of its two forms or modifications, that it is applicable as a water
wheel for obtaining motive power by the converse action, and erecting it in a
current or stream of water, with its shaft passing vertically up through suitable
carrying bearings and framing in a house built over the stream or current of water,
or it might be a floating house, pontoon, or other floating vessel or erection where
such motive power was required, as for the driving of electro-magnetic machines in
or on board of said erections for taking advantage of the power of running waters,
or rapid tidal flows and ebbs, and conveying the same to a distance through wires
as is well understood.
In all which cases the power of the water would drive the wheel by its pro-.
jecting blades or vanes in the direction of the current on either side, according to
that on which the cam was set to project them, and so drive the shaft in either
direction in which it might be required for the time being, as a right and left or
reversing motor.
And by another arrangement the first or horizontal modification might be con-
structed and used as a motive water wheel with its blades projecting out all round
(as in the case of some of the oldest forms of horizontal under-shot water wheels),
and have a segmental guard case fitted and enclosing the blades on or round two
thirds or three fourths of its circumference; and turned by strong eyes mounted to
revolve loose on the shaft close under and above the wheel, and actuated or turned
in the case or held in the desired position by a large toothed wheel or screw
wheel and pinion or screw on the lower or outer end of a controlling shaft, with
a hand wheel or lever on the upper or inner end of the said shaft, by which the
direction of turning the wheel would thus be controlled without the moving
blades of their cam action described in all the former modifications of this improved
propeller or motive power water wheel.