Improvements in Mechanism for and Mode of Marine Propulsion.
Year: 1896

page_text: Date of Application, 18th May, 1896-Accepted, 4th July, 1896
COMPLETE SPECIFICATION.
Improvements in Mechanism for and Mode of Marine Propulsion.
I, SIDNEY LAWRENCE, of 159 Queen Street, Melbourne, in the Colony of
Victoria, Australia, 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 invention relates to improvements in mechanism for propelling marine vessels
and in the mode of using said mechanism, and the object of the invention is to
produce an apparatus to which steam or other motive power may be applied, and
which will enable vessels to be propelled at greater speed than can be obtained by
any of the ordinary well-known means, or to propel such vessels at the same speed
but with a less expenditure of steam or other motive power. Furthermore, the
object of the invention is to employ apparatus which is not so liable to injury as
the exposed blades of screw propellers, all the essential parts of said apparatus
being wholly within the vessel's skin and, therefore, fully protecte 1. This protection
in the case of war vessels is of particular importance.
The improved mechanism comprises the construction and arrangement of parts
which is illustrated in the accompanying drawings, in the different figures of which
like letters of reference indicate similar parts, and in which Figure 1 shows a plan
of the mechanism I use in carrying out my invention, parts being shown broken
away to exhibit other parts more clearly; Figure 2 is a side elevation of parts of the
same mechanisin, but with the sides of the vessel not shown: Figure 3 is an end
elevation, partly in section, on the line 4-4 in Figure 1, as seen looking from
stern to bow.
Referring to the drawings-5 represents part of the stern end of a vessel, of any
suitable size or construction, taken on a horizontal section as deep beneath the
water line, as it is convenient to locate that part of the mechanism. 6 is a U-shaped
nietal tube, having wings or openings at each side of the head. 16 and 17 represent
the members or legs of the tube 6, and are of equal dimensions and parallel, one
member being on each side of and equi-distant from the longitudinal middle line of
the ship. The members 16 and 17 are open at the rear, and preferably terminate
at the skin 7 of the vessel, within which the tube is fitted as shown in the drawing.
A protecting or strengthening ring (not shown) may be attached to the skin 7
around the rear end of each tube. The pillows or supports 8 serve to keep the
tube fixed horizontally; 9 and 10 are two pistons or plungers fitting within 16
and 17 respectively (but not tightly) and reciprocated therein by piston rods 11
and 12 respectively. Any suitable antifriction surfaces may be employed for the
interior of members 16, 17 and for the rims of the pistons 9, 10, but in actual
working the piston rims will be surrounded by a film of water so that friction will
thus be largely eliminated.
The tube 6 has a central valve 13, by which it can be divided into two
independent portions, and has also two wings, 14, 15, one on each side, which
communicate with the vessel's exterior by means of reversible open mouthed
curved jet directors 18, 19, which form the outer ends of such wings.
For the purposes of illustration, one jet director, 18, is shown in the drawing
with its opening turned towards the bow, the other being shown with its
opening towards the stern, but in practice both jet directors are always turned
in the same direction as one another: when the vessel is going ahead they
both open to the stern; whilst when the vessel is required to go astern, they are
both turned so as to open towards the bow. The turning to point forward or

page_text: sternward, as the case may be, is accomplished simultaneously with the closing or
opening re-vectively of valve 13, which is shown in its closed position in the
drawings, but which is open when the jet directors are pointed to the stern-that
is under normal conditions.
Water-tight gates to close (when required) the open ends of members 16, 17, and
to close the waterways within the wings 14, 15, may be provided, to enable repairs
to be effected from within, or for other purposes. These gates are not shown in
the drawing, as their construction will be well understood, and they form no part
of this invention. The mouths 53, of the members 16, 17, and of the directors 18, 19,
may be protected by netting when desired. 20 represents stops for valve 13;
21, bevel gear wheel affixed to the valve spindle, and engaging bevel gear wheel 22,
which is secured to spindle 23, which is suitably journaled as at 24, and extends
transversely nearly the whole width of the vessel. 25 and 26 are two spur wheels
keyed to spindle 23, and engaging the sector wheels 27, 28, which are strapped or
fixedly secured to the inner ends of jet directors 18, 19 respectively. 29 is a chain
engaging a sprocket wheel 30, which may be integral with wheel 26, but of any
suitable size. 31, 32 are stuffing boxes through which piston rods 11 and 12 work;
and 34 and 35 are stuffing boxes which prevent the water having access to the
interior of the ship through the joints of the directors. 33 is a stuffing box through
which the spindle of the valve 13 is extended above the tube 6.
Suitable guides or bearings as 37, 38 are provided for the long piston rods 11, 12
to which are pivotally linked by pins 39 connecting rods 40 and 41 which are
linked to ends of vibrating arms 42 and 43 respectively, the other ends of said arms
being journaled or pivoted on the same axis 44 (as on a shaft) at the head of a
strong rigid frame 45. The arms 42 and 43 are bushed in sliding blocks 46 and 17
in which the crank pins 48 and 49 are journaled, the respective cranks being showu
by 50 and 51. These cranks are actuated by the main shaft 52 which is parallel
to the axis 44 and is journaled in the frame 45. Rotary motion is given to the
main shaft in any suitable manner, the drawings showing portions of connecting
rods as usable to actuate the shaft in conjunction with main or propelling engines
of the triple expansion type.
My mode of operating the pistons 9, 10 is to propel the same very rapidly in the
opposite direction to that in which the vessel is required to travel, whether it be
ahead or astern, whilst the return stroke is made much more slowly. Any suitable
ratio between these speeds may be secured by various means, the jet directors being
arranged to point as already explained.
If the vessel is propelled ahead by this mode of working the pistons great speed
may be secured; the pistons are preferably placed and operated so they work
alternately as nearly as possible, although their relative positions will constantly
vary (in a cycle) in consequence of their variations of speed.
The result of these varying positions is that the amount of fluid between the
backs of or connecting the two pistons will likewise vary, and when being
diminished will issue as jets from the directors 18, 19 and so help to propel the
vessel; when being increased additional fluid will be drawn in through the said
directors, the mouths of which should be as small as is compatible with this purpose;
the smaller they are the more rapid, and consequently useful will be the outward
intermittent jets from them. If the two pistons work as alternately as their
varying speeds will admit of, then several advantages are secured, as the power of
the main engines can be better utilized, and the amount of water representing the
maximum difference in the quantity of fluid which is between the pistons at
different times, will be at its minimum. This minimum quantity is dependent
on the relative speed of the fast and slow strokes, other conditions being the
same.
It will be clear that when travelling the vessel is propelled by the combination
of thrusts by solid pistons, and of intermittent jets of water.
As, when going asteru, valve 13 is dividing the tube 6 into two independent
parts, the water which is in advance of each piston during its rapid stroke bowward

page_text: will have only one outlet, and therefore will have greater force than if the valve 13
were open.
I find that the parts 37 to 52 will accomplish the purpose of actuating the
pistons in the mode aforesaid, but the angle between the crauks, 50 and 51, should
preferably be 180 degrees, i.e., they should be exactly opposite one another,
because, when in the latter position, the maximum difference in the quantity of
fluid which is between the pistons at different times will be at its minimum.
Taking cranks 50 and 51 as moving in the direction shown by arrow 54, then
each time a vibrating arm reaches a line tangential to the circle described by the
pin of the crank moving it (or parallel to such tangent) the piston corresponding
to such arm will be at one end of a stroke. Therefore, in fitting the pistons in
place they should be fixed accordingly. This is illustrated in the drawing, both
arms being at or parallel to such a tangent, and both pistous being at the end of
a stroke. It will be evident that the shorter the short arc joining the tangents is
(in other words the wider is the angle 55) the quicker will be the stroke of the
piston in one direction in proportion to the time occupied by the return stroke of
the piston, and that by using longer vibrating arms or longer cranks 50, 51, the
distance travelled in one piston stroke may be increased. In the drawing, the
ratio of the short arc to the long is 2; 1; therefore each piston will make a stroke
in one direction in half the time it will take to make the reverse stroke. It is
preferable to use arms as short as convenient.
When it is desired that the vessel should go astern, the main crank shaft 52
must be rotated in the reverse direction to that required for going ahead. This
can be accomplished by reversing gear as ordinarily used in marine engines. The
chain 29 may be connected to such gearing in order that the said chain may
operate the valve 13 and jet directors 18, 19 as already explained, as soon as the
reversing lever is actuated.
It will be obvious that the pistons shown in the drawings might be employed to
pump water out of the hull of the vessel into the sea, or vice versa, by connecting
to tube 6 suitable pipes provided with appropriate valves, but I make no claim to
cover any such device.
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 :-
1. In mechanism for the propulsion of marine vessels, a U-shaped horizontal
tube 6 having members 16, 17, opening towards the rear of the vessel, in com-
bination with wings 14, 15, at the respective sides of the tube head, and jet
directors 18, 19, forming the outlets to such wings, such directors being movable
so as to have their openings directed ahead or astern, substantially.as set forth.
2. In mechanism for the propulsion of marine vessels the combination with
the U-shaped tube 6, of valve 13, stops 20, stuffing box 33, gear wheel 21 outside
tube 6, on the extension of the spindle of valve i3, and gear wheel 22, ou
spindle 23, which extends transversely across the vessel and is journaled at 24,
substantially as set forth.
3. In mechanism for the propulsion of marine vessels, a valve 13, connected by
gearing with transverse spindle 23, in combination with spur wheels 25 and 26,
sector wheels 27 and 28, sprocket wheel 30, and chain 29, substantially as set forth.
4. In mechanism for the propulsion of marine vessels, the combination with
directors 18, 19, having mouths 53, of stuffing boxes 34 at the skin 7 of the vessel,
and stuffing boxes 35, at the inner ends of said directors, sector wheels 27 and 28,
spur wheels 25 and 26 on a spindle 23 which is connected by gearing to valve 13,
substantially as set forth.
5. In mechanism for the propulsion of marine vessels, a U-shaped tube 6, having
members 16, 17, open valve 13, wings 14, 15, and directors 18, 19, open to the
steru, in combination with reciprocating pistons 9, 10, piston rods 11, 12, and
stuffing boxes 31 and 32 substantially as set forth.

page_text: 6. In mechanism for the propulsion of marine vessels, a U-shaped tube 6, having
members 16, 17, closed valve 13, wings 14, 15, and directors 18, 19, open to the
bow, in combination with reciprocating pistons 9, 10, piston rods 11, 12, and
stuffing boxes 31 and 32 substantially as set forth.
7. In mechanism for the propulsion of marine vessels, the pistons 9, 10, having
piston rods 11, 12, working in guides or bearings 37, 38, and linked by pins 39 to
connecting rods 40 and 41, in combination with vibrating arms 42 and 43,
journaled on the same axis 44, said arms connected to cranks 50 and 51, on main
shaft 52, substantially as set forth.
8. In mechanism for the propulsion of marine vessels, the vibrating arms 42, 43,
journaled at one end on an axis 44, and linked at their other ends to connecting
rods 40, 41, in combination with sliding blocks 46, 47, crank pins 48, 49, journaled
in said blocks and cranks 50 and 51 on a main shaft 52, whereby the vibrating
arms are adapted to successively impart fast and slow motions to the connecting
rods 40 and 41, substantially as and for the purposes set forth.
9. In mechanism for the propulsion of marine vessels, a main shaft 52, having
two cranks fixed diametrically opposite one another in combination with an axis 44
parallel to shaft 52, and vibrating arms 42, 43, connected to such axis, also
connected to said cranks, and also connected to mechanism whereby pistons 9, 10,
may be successively reciprocated so as to make fast and slow strokes substantially
as set forth.
10. In the propulsion of marine vessels, the method of propelling the same
consisting in reciprocating two pistons 9, 10, in a tube 6 having members 16, 17,
wings 14, 15, and directors 18, 19, in such manner that the strokes of the pistons
in the opposite direction to that in which the vessel is to be propelled shall be
made more quickly than the return strokes, substantially as set forth.
11. In the propulsion of marine vessels having a tube 6 with valve 13,
members 16, 17, wings 14, 15, and directors 18, 19, the method of propelling the
same ahead consisting in opening valve 13, turning directors 18, 19 so that their
mouths shall open towards the stern, and then reciprocating pistons 9, 10 within
members 16, 17, rapidly from front to stern and more slowly in the reverse
direction, and so that the strokes of one piston in a given direction will be made
alternately with the strokes of the other piston in that direction, substantially as
set forth.
12. In the propulsion of marine vessels having a tube 6 with valve 13,
members 16, 17, wings 14, 15, and directors 18, 19, the method of propelling the
same astern consisting in closing valve 13, turning directors 18, 19 so that their
mouths shall be open towards the bow, and then reciprocating pistons 9, 10 within
members 16, 17, rapidly from stern to bow and more slowly in the reverse direction,
and so that the strokes of one piston in a given direction will be made alternately
with the strokes of the other piston in that direction substantially as set forth.
13. The general arrangement and combination of parts of the improved
mechanism for marine propulsion, consisting of the parts herein before described
and illustrated by the reference figures 6 to 52 on the accompanying drawings.
Dated this 18th day of May 1896.
WHEATLEY & MACKENZIE,
40 Chancery Lane, London, W.C., Agents.