Improvements in the Propulsion of Boats, Launches, and other Light Vessels, and Appliances or Mechanism Connected therewith.
Year: 1886

page_text: Date of Application, 28th Apr., 1886.
Complete Left, 27th Jan., 1887.
Complete Accepted, 1st Mar., 1887.
Improvements in the Propulsion of Boats, Launches, and other Light
Vessels, and Appliances or Mechanism Connected therewith.
I, ALEXANDER MCRAE, of 13 Nicholson Street, Greenock, Renfrewshire, Engineer
do hereby declare the nature of this invention to be as follows
My invention has reference to special improvements in the construction, arrangement
and combination of the parts of mechanism for and connected with the propulsion of
the screw propellers of launches and other small boats or vessels, specially applicable
for being driven by the human fect or hands or by small motive power engines; and
mainly with the object of reducing the friction of the working parts of such mechanism
so that the maximum amount of power exerted is developed in propelling the screw
propeller and boat or vessel.
The nature and novelty of my improvements consist first in mounting and fitting
the screw propeller shaft within a long hollow water tight tube without stuffing boxes;
and screwed or otherwise secured water tight through the stern post preferably near
the lower part, and carried up at an angle until the open end is sufficiently higher
than the level of the water outside, so that no water can get into the boat or vessel
through this tube.
The outer stern end of the propeller shaft would have the screw propeller keyed or
otherwise mounted on its overhanging end, and have the inner surface of its boss
fitted with a collar recessed ring of anti-friction rollers projecting out slightly beyond
the collar boss, so as to bear and roll on the outer surface of a thrust bush or collar
secured on the outer end of the stern post or tube of the shaft and so as to receive all
the thrust of the shaft on a rolling action without friction. The collar bush within the
tube of the shaft would also be fitted with a ring of antifriction rollers round the neck
of the shaft to act as an anti friction neck bearing, both of which sets of anti-friction
rollers would be lubricated by the water outside. The upper inner open end of the
propeller shaft and its tube might also be similarly fitted with a bearing of anti-friction
rollers as an inner neck bearing, or journal bushes might be fitted at this end, in either
case lubricated by a suitable oil containing chamber or receptacle. The inner over-
hanging end of the propeller shaft would by one arrangement be fitted with an anti-
friction bevel pinion, preferably formed and fitted with grooves and rings of india

page_text: rubber or other equivalent which would give a noiseless gripping action; and be driven
by a vertical bevel wheel secured on a horizontal transverse crank shaft with pedal or
treadle cranks on its extreme ends when it was to be driven by the human feet, this
crank shaft being carried in suitable pillow blocks projecting up from the inner bottom
frames of the boat or vessel, fitted with rings of anti-friction roller bearings.
The person actuating the crank shaft would sit on a seat erected over the propeller
shaft with his legs projecting forward on each side of the gearing at an angle down-
wards and having his feet resting on and turning the pedals and his hand or hands
free to work a steering handle on either side connected by a light rod or wire cords
led to the tiller of the rudder, which would be mounted on pintles to the stern post
above, and have its steering blade projecting down abaft the propeller.
By another arrangement, the crank shaft with the bevel wheel on it might be
mounted low down near the bottom of the boat, and have a short fore and aft shaft
with a bevel pinion on it working into the bevel wheel on the crank shaft, this short
shaft driving the propeller shaft by an endless pitch chain and sprocket or chain
wheels mounted on the short shaft and the inner end of the propeller shaft, or by
noiseless friction or toothed spur wheels or it might be grooved wheels and bands
or other equivalent gearing. Or the crank shaft itself might have a grooved driving
wheel on it with bands or cords guided or led over a grooved pulley on the inner
overhung end of the propeller shaft.
And although the crank shaft has been described as driven by the feet, it could be
mounted higher in the boat on its bearings and be turned by hand cranks when
preferred to driving by the feet.
By another arrangement which would not require the long tube of the propeller
shaft, this shaft might be carried in bearings and led aft above the water line, and
have a chain pulley keyed on its outer end beyond the stern post, and which by an
endless chain would actuate a corresponding chain pulley on the boss of the propeller,
which would be mounted on a strong fixed axle projecting aft near the bottom of the
stern post.
These propellers when so placed near the keel of the boat would preferably have only
two blades, so that they could be placed horizontally to allow of the boat being pulled
up on its keel on shore clear of and without touching the propeller; and a mark or
index could be formed on the driving pinion on the inner end of the propeller shaft,
so as to show when the propeller was set athwart ships, so as to run the boat into
shallow water.
Or in the modification in which the propeller is mounted on a fixed axle or stud the
frame of this might be fitted so as to be lowered and raised by a screw or otherwise to
or from the keel of the boat.
For launches or large boats where considerable power was required, a small engine
could be used to.actuate the main driving crank shaft; or two, three or more inci
could actuate this through treadles, or through crank and tread shafts, of their own,
or hand crank shafts, so arranged, connected to the main shaft by chain wheels or other
gearing. And where the boats had to be used in shallow water twin screws may be
fitted, each driven by a propeller shaft and its gearing from the main crank shaft in
the same manner as describel for the one screw,
It will be seen that these arrangements although described for working the screw
propeller or propellers at the stern of the boat, are equally applicable for being applied
to work the propellers at the bow or fore part of the boat or vessel.

page_text: Improvements in the Propulsion of Boats, Launches, and other Light
Vessels, and Appliances or Mechanism Connected therewith.
I, ALEXANDER MCRAE, of 13 Nicholson Street, Greenock, Renfrewshire, Engineer,
do hereby declare the nature of my Invention and in what manner the same is to
he performed to be particularly described and ascertained in and by the following
statement in writing reference being had to the accompanying Sheets of Drawings,
and to the reference letters and figures marked thereon, that is to say :-
My Invention has reference to special improvements in the construction, arrange-
ment and combination of the parts of mechanism for and connected with the propulsion
of the screw propellers of launches and other small boats and vessels, specially
applicable for being driven by the, human feet or hands or by small motive power
engines and mainly with the object of reducing the friction of the working parts of
such mechanism so that the maximum amount of power excried is developed in
propelling the screw propeller and boat or vessel.
And in order that my said Invention, and the manner of performing or carrying the
same into effect or practice may be properly understood, I have hereunto appended
two Sheets of explanatory Drawings, in which the same reference letters are used to
indicate corresponding parts in all the figures where shown. Figures 1 and 2, on
Sheet 1, are a sectional side elevation and plan respectively, of a boat A, as fitted with
one arrangement of my improvements; and Figure 3, a transverse section taken near
the line 1...1 in Figure 1. Figures 4 and 5, show a sectional elevation and end
section respectively of the screw propeller end of its shaft B, and thrust bearing D, D'
at the stern of the boat A, to an enlarged scale.
三
Referring to these Figures 1 to 5. the nature and novelty of my improvements
consist first, in mounting and fitting the screw propeller shaft B, within a long hollow
water tight tube C, without stuffing boxes; and screwed or otherwise secured water
tight through the stern post A¹, of the boat A, to the thrust bearing D bolted to the
stern post A outside as seen particularly-in Figure 1, and in detail in Figures 4 and 5,
preferably near the lower part, and carried up at an angle until the open end of the
tube C, is sufficiently higher than the level of the water outside, so that no water
can get into the boat or vessel A, through this.tube C. The outer stern end of the
propeller shaft B would have the screw propeller S screwed, keyed, or otherwise
mounted on its overhanging end, and have the inner surface of its boss S¹ fitted with
a collar or recersed ring of anti-friction rollers R, projecting out slightly beyond the
collar boss, S so as to bear and roll on the outer surface of a thrust bush or collar D, D',
secured on the outer end of the stern post A', and tube C, of the shaft B, and so as to
receive all the thrust of the shaft B, on a rolling action without friction. The collar

page_text: bush D, of the tube C of the shaft D, is fitted with one two or more rings of anti-
friction balls or rollers R¹ to form a neck bearing D, D₁, preferably formed in two
parts with a screwed down cover D¹ as seen particularly in Figure 5; both of which
sets of antifriction rollers R, R1, are lubricated by the water outside. The upper inner
open end of the propeller shaft B, and its tube C, is preferably similarly fitted with a
bearing E of antifriction rollers ¹, as an inner neck hearing, or journal bushes might
be fitted at this end, which in either case may be lubricated by a suitable oil-containing
chamber or receptacle. The inner over-hanging end of the propeller shaft B, is by
one arrangement fitted with a bevel pinion, which is driven by a vertical bevel
wheel secured on a horizontal transverse crank shaft a with pedal or treadle cranks a¹
on its extreme ends to be driven by the human feet, this crank shaft a being carried
in suitable bearing blocks ², which may also be fitted with rings of antifriction roller
bearings R¹, secured to longitudinal bars a³, and to the cross beam seats A³ of the
boat A, but this gearing might be carried by suitable frames F, projecting up from
the frames A of the boat A. In place of the toothed level wheels b,, these
made in the form of antifriction groove or other wheels, such as grooved rings of
india-rubber or other equivalent noiseless friction driving wheels.
may be
The person actuating the crank shaft a would sit on a shifting seat G, erected on
a suitable light frame "G', secured to the transverse beam seats A², over the inner end
of the propeller shaft B with his legs projecting forward on each side of the gearing
at an angle downwards, and have his fect resting on and turning the pedals a', a
leaving his bands free to work a steering handle H secured on the top of the spindle H₁
in front, carried in bearings in the frames G¹ and A³ and connected by a lever H² to
light rods or wire cords led through an arrangement of guide pulleys ', back over
both gunwales of the boat A to the tiller I of the rudder 1, which would be mounted
on pintles to the stern post A' above, and have its steering blade projecting down
abaft the propeller S. The steering spindle H has fitted at its lower end a stop
lever H³, with stops at secured to the bar frames a³, which prevent the steersman
from carrying the rudder too far to port or starboard, These steering wires and
fittings,, might be led along within the boat.
By another improvement, not shown in the Drawings, the crank shaft a with the
bevel wheel on it might be mounted on framing F low down near the bottom of the
boat, and have a short fore and aft shaft under the propeller shaft with a bevel pinion
on it working into the bevel wheel on the crank shaft, this short shaft driving the
propeller shaft by an endless pitch chain, and sprocket or chain wheels mounted one
on the short shaft and one on the inner end of the propeller shaft in place of the bevel
pinion b, or by noiseless friction or toothed spur wheels or it might he grooved wheels
and bands or other equivalent gearing in place of the bevel or chain wheels. Or the
crank shaft itself might have a grooved driving wheel on it with bands or cords
guided or led over a grooved pulley on the inner overhung end of the propeller shaft.
Figures 6 and 7 on Sheet 2, are a sectional elevation and plan respectively, and
Figure 8, a transverse section, of an arrangement and combination of the parts of my
improved mechanism as applied for being driven by hand by the persons propelling.
the boat or vessel. In this arrangement the gearing shaft a driving the screw
propelling shaft B. is mounted on longitudinal frames a³ on standards F projecting up
from the floor frame of the boat A, and has no foot crank pedals mounted on it, but
instead has a chain wheel k, k, mounted at the side of the driving bevel wheel B¹, by
which it is driven through a chain wheel, and chain ³, from the hand crank
shaft K; with cranks and handles K', on its overhung end, so as to be driven by the
person sitting on the centre of the transverse beam seats A³, using both, his hands on
the crank handles K. This driving-shaft K is carried in bush bearing blocks L
secured on a plate frame over the wheel driving shaft a, by adjustable screw
standards L² from the lower longitudinal plate frame a secured to the underside of the
main beam As, and. at the forward end to the standards F, all so as to allow freedom
for the person driving the cranks with his hands to steer with his feet in front of him.
In this arrangement the steering mechanism consists of a swiveling bar spindle M
carried in footstep and journal bearings secured to the floor frames, and to one of the

page_text: cross beams A, having a transverse bar N secured to it a little under the beam A',
with adjustable screw foot treads », at a width to suit the feet of the person, so that he
can swivel this bar N by his feet to steer the boat through rods or wire cords h
connected to the ends of the bar N, and led up to the tiller I, over guide pulleys and
eyes ', stops a being also provided to prevent the lever N being swivelled too far by
the feet, this arrangement being otherwise substantially as shown in reference to
Figures 1 and 2 on Sheet 1. Both of these arrangements for steering, enables the
person driving the mechanism and propeller to steer in front of him while seeing all
round the bow and sides of the boat.
Although only one driving shaft K K has been shown in this arrangement, it is to
be understood that two or more might be fitted on frames corresponding to L, L', I,
adjacent to other beam seats in the boat, so as to be driven by other persons when that
was desired, and chain wheels as might be mounted on the shaft and corresponding
chain wheels on the said extra driving shafts with chains leading down to these
wheels or other equivalent arrangements of chain gearing. Figure 9, shows a
sectional elevation of the inside end bearing E, of the screw propeller shaft B, corre-
sponding to Figure 1 on Sheet 1, and Figure 6 on Sheet 2, but to a large scale, to
Show the details of construction more clearly, and is substantially the same as the
outside end bearing D, D', described in reference to Figures 4 and 5 of Sheet 1,
except that it is supported on a horizontal flange E, instead of a vertical flange, to
the frame, and has no thrust antifriction ring of rolling balls R, but has the upper
cover D removable in an equivalent manner, with two sets of rings of antifriction
rolling balls R, within grooves as a circumferential bearing to this inner end of the
screw shaft B. But although rings of balls have been shown in these bearings,
Figures 4, 5, and 9, it is to be understood that rings of small rollers might be used,
or rollers in rotating rings in lien of the balls.
શ
By another arrrangement, not shown in the Drawings, which would not require the
long tube, of the propeller shaft B, this shaft might be carried in bearings and led
aft above the water line, and have a chain pulley keyed on its outer end beyond the
stern post A', and which by an endless chain would actuate a corresponding chain
pulley on the boss of the propeller-S and which would be mounted on a strong fixed
axle projecting aft near the bottom of the stern post.
These propellers S, when so placed near the keel of the boat A, as described would
preferably have only two blades, so that they could he placed horizontally to allow of
the boat being pulled up on its keel on shore clear of and without touching the
propeller; and a mark or index could be formed on the driving pinion &, on the inner
end of the propeller shaft B, so as to show when the propeller was set athwart ships,
so as to run the boat into shallow water. Or in the modification in which the
propeller S is mounted on a fixed axle, or stud, the frame or bracket carrying this
might be fitted so as to be lowered and raised by a screw or otherwise to or from the
keel of the boat. Or in some cases instead of having to move the propeller, a portable
strong piece might be fitted in front of the propeller on the underside of the stern of
the keel, as shown dotted-in, in figure 1, secured by an iron strap to the stern post
and keel, as dotted-in at S2 to protect the propeller S.
For launches or the larger sizes of boats the shaft a might be driven by small motive
power engines as a crank shaft.
It will be seen that these arrangements although described for working the screw
propeller or propellers at the stern of the boat are equally applicable for being applied
to work the propellers at the bow or fore part of the boat or vessel in an equivalent
manner.
Having now particularly described and ascertained the nature of my said Invention
and in what manner the same is to be performed, I declare that what I claim is :-
First. The mode and means of, or arrangement and combination of gearing and
mechanism for driving the screw propellers of boats, launches, and other light vessels,
substantially as herein Described in reference to and shown in the accompanying
Drawings.

page_text: Second. The arrangement and combination of gearing and mechanism driven by
the human feet or hands for and connected with the propulsion of boats by screw
propellers, either with or without the arrangements of steering, substantially as herein
Described, in reference to and shown in the accompanying Drawings.
Third. In boats, launches, and other light vessels, the enclosing of the screw
propeller shaft in a tube at an angle, to lessen friction and prevent the water getting
into the vessels, or requiring stuffing-box, stern tubes, substantially as herein Described,
in reference to and shown in the accompanying Drawings.
Fourth. In boats, launches and other light vessels, the mounting of the screw
propeller shaft in antifriction rolling bearings, substantially as herein Described, in
reference to and shown in the accompanying Drawings.
W. R. M. THOMSON & Co..
Agents.