Improvements in Boat-lowering Mechanism.
Year: 1898

page_text: [Communicated from abroad by CARL SCHNEEMANN, of the Schlachthof, Bremen, in
the Empire of Germany, Director of Municipal Slaughterhouses.]
Improvements in Boat-lowering Mechanism.
I, PHILIP ARTHUR NEWTON, of the Office for Patents, 6, Breams Buildings,
Chancery Lane, in the County of London, Patent Agent, 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:-
The present invention relates to boat lowering mechanism comprising a windlass
and specially arranged davits, which are thrust out by special levers to such a distance
that they are able to move overboard and downwards by their own weight and that
of the boat.
In Fig. 1 of the accompanying drawings is shewn a half section of a modern
passenger steamer of about 100 metres in length, fitted with boat-lowering
device according to this invention. The particular windlass shewn in this drawing
is supposed to be mounted on the deck at the end of the boat or rather between two
adjacent boats.
Fig. 2 shews the way in which the windlass (which is the chief object of the
present invention) is mounted on the upper deck at the end of a boat.
Fig. 3 is a central vertical section through the windlass.
Fig. 4 is partly a longitudinal section thro' the windlass, and partly a side view, the
steam engine being removed.
Fig. 5 is a rear. view of the windlass; and
Fig. 6a plan view of the same, shewing the whole driving gear in horizontal
section.
Fig. 7 shews, in top view, the part cut away in Fig. 6.
Figs. 8, 9, and 10, are views of various parts of the windlass, which are not shewn
with sufficient clearness in the main figures.
Fig. 11 shews, in section, the arrangement of the rods which thrust out each boat
davit separately.
Fig. 12 is a cross section of Fig. 11; and
Fig. 13 is a diagrammatic representation of the steam engine by which the
windlass may be suitably driven. This engine may however be replaced by any other
reversible motor, provided it be simple, reliable, and light.
Figs. 14 to 16 shew the slide valve (illustrated in Fig. 13) in various positions.
Fig. 17 shews a further device for connecting the windlass with the projecting
levers.
In Figs. 1 and 2, a is the boat, which hangs in two davits b. In Fig. 2, only one
of these two davits is seen; both, however, are equidistant from the ends of the
boat. The boat itself rests upon the so-called chocks c, upon which it is held by a
device having no direct connection with the present invention whatsoever, said device
permitting instant release of the boat from both its chocks, but at the same time
making all movement of the boat during the voyage impossible.

page_text: A indicates, in Figs. 1 and 2, the windlass. For the sake of clearness, the windlass
is shewn in general outline only. The davits are pivotted at d, and rest, when the
boat is on the chocks, on the bearings provided on the latter. When the boat is to
be lowered, and is loosed from the chocks, the rods e (of which one lies against each
davit) are thrust outboard, and thereby the davits, together with the boat, are
brought into the dotted position II of Fig. 1. When this position has been attained,
the rods e cease to move any further, and the davits rest now at their upper ends
upon the weights f of the draught rope g.
As the rods e are thrust out, the windlass has to give out the necessary quantity of
rope. By suitably bending the davits at h, it may be so contrived that, for a uniform
amount of forward motion of the rods e, the upper free end of the davits upon which
the boat bangs may move forward only so far as to necessitate an amount of rotation
of the rope drum corresponding to the amount of advance of the rods e.
When the davits have taken up the position shewn in dotted lines in Fig. 1, they
sink, even during the greatest inclination of the ship's hul! toward the opposite side
of the ship, still further down in the direction of the arrow i, until they arrive at the
position III, shewn in dotted lines, in which they are held by chains. The boat is
now let down to the water by a paying out of the rope g by the windlass, and the
boat tackles are cast off at the proper moment. The casting off tackle may be of any
kind suitable for the purpose, and forms no part of the present invention.
In Figs. 3 to 6, is the windlass drum upon which the ropes g, one for each davit,
are wound. The drum turns in bearings n, and is rotated by the worin wheel o fast
therewith. The windlass is shewn in the position corresponding to the drawn
position of the boat in Fig. 1, and in which this latter is lying upon the chocks c,
ready for lowering.
On bringing the hand valve p (Fig. 13), by means of the lever g (Figs. 7 and 13),
to the position shewn in Fig. 14, the engine starts working, and, by means of two
worms and 8 and the worm wheels t and o, winds the rope drum in the direction of
the arrow (Figs. 4 and 6), and thus pays out the rope g. Simultaneously the
friction clutch v (which does not turn, but slides endwise upon the engine shaft w)
causes the mitre wheel x (Figs. 5 and 6), which is loose upon the shaft w, but
incapable of sliding endwise thereon, to turn. turns, through a suitable train of
gears y y², a horizontal shaft a¹ (Figs. 5, 11, and 12), which in its turn turns, by
means of two worms b¹ (only one of which is seen in the drawing), the worm wheels c¹.
The power-transmitting connection of the wheel y with the wheel y2 may be effected
by means of a powerful spring 2², in order that the shaft a¹ may not be set in motion
with a sudden shock, when coupled up by the clutch v, t, while the engine is working.
By the rotation of the worm wheels c¹, whose bosses are threaded internally, both
rods e (one of which, only, is shewn, for the sake of clearness) are simultaneously
thrust outboard in the direction of the arrow o¹. The free outer end of each rod e is
provided with a roller d¹ which bears against each davit b. During the same time,
a worm g¹ and a worm wheel h¹ and shaft i¹ (Figs. 5 and 7) are set in motion by
worm wheels f, for the purpose of bringing the clutch v and wheel x in and out of
contact with each other, by means of the rod m¹ and the lever pivotted at /¹, when
the projecting rods e are sufficiently thrust outboard, when lowering, or when
hoisting up the boat, to take it on board, by manoeuvring with the windlass, for the
davits on the point of being raised to bear against the rollers d¹ of the said rods e.
The worm wheel h¹ rotates simultaneously with the shaft i¹ a screw of very small
pitch, e.g., eight threads to the inch (English). Upon this screw n' is a sleeve o¹,
which, as soon as the engine B is started, travels slowly in the direction of the
arrow pl (Fig. 7). This sleeve o¹ is connected with a second, very short-threaded
sleeve q' of much higher pitch (e.g., 80 m.m.), which as soon as the rods e are on the
point of taking up the dotted position II in Fig. 2, picks up a thread 1 fast on, or
in one piece with, the shaft . As i¹ rotates continuously with the shaft ¹, this
screw immediately takes into q', and moves (by means of this sleeve) the shaft
suddenly in the direction of the arrow s¹. Simultaneously, the lever is rocked on
its pivot k¹, and thereby the, friction clutch v, t¹ is thrown out of contact. The con-

page_text: struction n¹, s¹, 71, q¹, may be so designed that the release of the clutch may be
effected in a second, or only a fraction thereof, without subjecting the threads 7+1 gl
to any serious strain. The engine may be run at 300 revolutions per minute, and
the boat descend or ascend about 2 metres during that time. To secure the
clutch v,
in the end position, there is provided a lever v1 fixed to a rotating
shaft u¹ (Fig. 7), which takes into one or other of the grooves w¹, according to the
position of the shaft. Shortly before the screw q¹ engages with the screw 1, a small
nose x on the sleeve o¹ (Fig. 5) lifts, by means of a lever y¹, the lever v¹ out of the
groove w¹, to let it fall again, when the screw has completely passed thro' q'. The
steam engine B has, from that moment in which the point of suspension of the boat
on the davits passes over the turning (or dead) point d, no work to perform. From
this moment the davits sink, together with the boat, of themselves, till the davits
are held by the chains and the boat hangs out so far over the water as to allow of
its being released. That the boat may fall more or less according to the inclination
of the vessel to the surface of the water, and the windlass so pay out more or less
rope, has been already mentioned. The engine B, during this time, has only to
empty the rope drum, and, by suitably regulating the pitch of the screws r and 8,
the boat may be prevented from unwinding the drum by its own weight without the
use of a brake. In case of necessity, the braking may be done by simply reversing
the engine. By using piston valves in the steam engine, there can be no difficulties
in this arrangement.
When the boat is to be hoisted up out of the water and deposited on the chocks,
instead of being lowered, the lever p is brought from the position in Fig. 15, in
which the engine is at "stop," to the position shewn in Fig. 16, so that the engine
runs backwards. The hand lever q now takes the position shewn dotted in Fig. 7,
and an arm a², projecting from its fulcrum e¹, bears against one end of an eye formed
in the end of a longitudinally sliding rod c². The drums now wind up the ropes g,
and, consequently the boat is drawn up; the screw q³ travels, by reason of its reversed
direction to the arrow p¹, along the rod ¹, the nose a lifts the lever v¹ out of the
groove to screws itself (both threads meeting in exactly the same manner as they
separated from each other), without the slightest difficulty, immediately and rapidly
through g', and thereby moves quickly the rod in the reverse direction of the
arrow 8¹, so that, with the help of the rods ¹ m¹, the clutch v, t¹ comes into
operation.
;
The teeth of the clutch may be flat, headed, and directly in contact, without
incurring the slightest disadvantage, for two reasons,-First, the rotating clutch
teeth revolve for a fractional portion of a second past the rigid clutch teeth, so that
the actual friction taking place only lasts a very small period of time; secondly, the
rod n¹, by reason of the arrangement of the small springs g², can move so far in an
axial direction as the nut q¹ travels along the screw during the friction against
each other of the clutch members. In the most unfavourable circumstances, the
compression of the springs produced amounts to about one millimeter.
...During the instant in which the coupling takes place, the shaft a¹ is again rotated,
and draws, by means of the construction already described (Figs. 11 and 12) the
rods e inboard, as the davits are moved in the same direction by the rope. To avoid
the coupling taking place while the engine is running at full speed, the shaft ¹ is
prolonged in the direction of the arrow p¹, for such distance as to enable it to receive
upon its end a lever d². In the instant during which the nose turns the shaft
through the lever y¹, the lever d² pulls the rod c², and when the hand lever q stands
at backwards," draws this latter round in the direction of the arrow for such a
distance that the hand valve p is brought nearly to its "stop" position, as illustrated
in Fig. 2, and, by strongly throttling the steam, thus causing the engine to run
slowly, without the man at the lever having to do anything, or, rather, being able to
do anything.
When the coupling of the clutches vt has taken place, which may be known by
the ear, and the position of the small lever ², by the man at the windlass, the lever q

page_text: may be pulled right over to "backwards," and the boat rapidly drawn along with its
davits.
As soon as the boat is over the "chocks," the man at the windlass must of course
move the hand lever q back, so that the machine may go very slowly, or come to
stand at "stop." If necessary, a simple device may be adapted to the apparatus,
which, at the required moment, will suddenly and completely shut off the admission
of steam to the engine, without the cooperation of the man attending to the wind-
lass, so that the engine will then be stopped at once.
.
When the boat is to be lowered upon a rough sea, in case the ship is to be aban-
doned, it may easily happen that the man standing at the hand lever q may slip
down or fall on the deck, in consequence of the violent motions of the vessel; or may
leave the windlass; or, lastly, through any exterior cause, may be rendered in-
capable of performing the duty assigned to him; in this case, there will come into
action a small piston f, which automatically draws back the slide p into the position
shown at Fig. 13, so soon as the lever q is no longer in the power of the attendant,
or anyone else who may be on the vessel, the said piston f being coupled fast
with the hand valve p, and always under full steam pressure from the boiler.
When the hand valve p is so situated that, on account of compression occurring in
the engine, it cannot be moved from its seat (a piston valve fulfils this condition in a
simple and efficacious manner), the windlass (so soon as the attendant has no longer
the lever under his control) remains motionless, even in the unlikely event that the
descending boat, whilst overcoming all friction therein, should itself, by its mere
weight, tend to turn the windlass.
The engine cannot then, so soon as the hand valve has taken the position of
Fig. 13, drive any steam that may be in front of the piston into the surrounding
atmosphere, and this becomes therefore so strongly compressed immediately after the
closing of the exit channel by means of the valve p, that the counter pressure
against the steam piston makes a further motion of the windlass impossible."
In one of the pipes leading from the hand valve p to the cylinders, a small air
valve g may also be adapted, which, in case the machine should develop a vacuum
in one of the said channels, would allow air to enter. As this air, in the position of
the valve p represented at Fig. 13, cannot be driven out into the atmosphere, it has
the effect of driving that just mentioned, and acting as an air brake, in the engine,
even in the case that the steam in the engine at the time of the closing of the
valve should condense, and thereby the "braking" action can no longer be
exerted.
The air compression in the engine becomes, before the boat has fallen many inches
inore than was desired, so strong, that any further falling of the boat is completely
prevented.
The rod which moves the valve p to "stop," when the clutch is to be coupled up,
may also be made to act upon a throttle-valve located in the steam channel. In this
case, the rod may be connected with the throttle valve, in place of a slot, by means
of a closely adapted joint or arm, so that the valve in either case (that is, either when
the clutch is to be coupled or uncoupled) shall be closely shut by means of the nose
or projection x¹. The clutch v t¹ may also be replaced by a suitable friction clutch.
The windlass above described may be in such-wise modified, that it may be made
capable of being worked by hand. Such a construction need not be illustrated, as
this is a thing that is within the capacity of any machine constructor, and could not
form the subject of a patentable invention.
Again, the push rods e also may be moved outwards and inwards by means of
toothed gearing, instead of by a windlass. In this case, it is possible to dispense
with the parts represented by the screws r¹, n¹ q¹, and to use, instead thereof, the
construction shown at Fig. 17, in top view, and partial horizontal section. In this
case represents the toothed wheel, which is pivotally mounted upon the shaft a¹,
located under the deck of the vessel, and longitudinally thereof, but is not movable
axially. This toothed wheel takes into the teeth provided on the underside of the
rode, the teeth not being visible in the drawing, because the rod e is seen from

page_text: above. This latter is mounted in the bearings ƒ³, g³, crosswise of the vessel.
With
the toothed wheel is rigidly connected, in the arrangement represented in the
drawings, a clutch wheel h³, capable of taking onto another clutch wheel 23 located
on the shaft a¹, and capable of axial, but not rotary, movement thereon. ³ is moved
by means of the bell-crank lever c³, the fork of which takes into the groove of the
clutch wheel 3. The lever is capable. of rocking on the fulcrum... When the
boat is to be raised, the rods e, as indicated at Fig. 1, are pushed quite out. During
the winding up, the davits b come into the position represented by II in Fig. 1, and,
whilst they approach nearer to the vessel, and come into position against the
rollers of the rods e, push these latter (e) into the vessel.
At this time, the toothed wheel first begins to rotate with the clutch. wheel ha
loose, corresponding to the position represented at. Fig. 17. A piece 13 attached to
the rod c, however, comes against a rigid pin 63 of the lever 3, after e has made a
slight movement inwards by means of the davits, and thus turns this lever. (see
Fig. 17) around to the right,, so that the clutch wheel ³ comes into engagement with
the clutch wheel h³. The clutch wheels are preferably tapered at their free ends in
the direction of their axes, so that they shall not butt against each other.
So soon as the coupling up has been effected, c³ is swung so far round to the right
that the vertical lateral surface m³ of the toothed rod e slides along on the pin 63, and
thereby prevents the automatic uncoupling of the clutch wheels h³, 13. The clutch
remains, therefore, so long in effective connection, until the rods e have been moved
entirely inwards, and, later on, for the purpose of putting out the boat, have been
pushed outwards again.
The
Whilst the davits are being raised, the shaft a¹ turns in the direction of the
arrow m, as it is permanently connected with the winding drum (which takes up the
wire rope g) by means of toothed wheels, or the like, and continually turns whenever
the winding drum is rotated. When the rods e are pushed out, and come nearly to
their outermost position, a projection or a pin a³ of the rods e comes against the lever
arm c, and carries it with it until the clutch wheels ³, i³, are released, and the
driving of the toothed wheel e³ through the shaft 3 in consequence ceases.
windlass itself, and with it the shaft n³, may now continue to turn for any length of
tine, and in any direction, but the clutch wheels ³ ³ will not come into effective
action until the rods e have been again pushed backwards a little by means of the
davits, and, as a consequence thereof, have coupled up the rotating shaft a¹ with the
toothed wheels e³ by means of the clutch wheels h³ ³. The clutch wheels h³ ³ are
The functions of the lever c³ ³ will, however,
merely given by way of example.
remain the same in this case.
Having now particularly described and ascertained the nature of the said
invention and in what manner the same is to be performed, as communicated to
me from abroad, I declare that what I claim is:
1. Windlass for the taking on board ship, and the letting out therefrom, of boats
for use on vessels in which the boat's davits run under the planking of the boats, and
are so mounted (pivotally) on the vessels, that they are capable of being pushed
outwards, together with the boat, crosswise of the vessel, by means of push-rods, and
characterized by the following features, viz. :-that the winding drum () which winds
up the draught rope (g) for each boat, is connected with the push rods (e) by means
of a clutch, which at the right moment, becomes automatically either engaged or
disengaged, as required, the davits remaining in contact with the said rods e, when a
boat is being lowered until such a distance from the vessel is reached, that they are
able to move further of their own accord, under the weight of the boat, in the
direction given to them by the rods.
•
2. In combination with a windlass of the character referred to in Claim 1, an
arrangement for the automatic coupling up and uncoupling of the clutch v t¹ at the
moment in which the davits, when a boat is being taken on board, comes against the
push rods, whilst they become disengaged therefrom, when the boat is being lowered,
and characterized by the following features, viz. :-a screw (n¹) of slight pitch,

page_text: turning simultaneously with the winding drum (1), the nut of which, at the moment
in which the coupling up (or uncoupling) of the clutch vt is to take place, brings a
second nut (q), of much greater pitch, into connection with the corresponding short
screw, also turning simultaneously with the drum l, so that the screw (which
passes through q¹) is capable of changing the position of the movable portion (v) of
the clutch vt by means of a suitably formed rod or bar 11 m³.
3. In combination with a windlass of the kind referred to in Claims 1 and 2, a nose
or projection a moving simultaneously with the nut o', which nose or projection, at
the moment in which the rods e reach their outermost position (or, as the case may
be, commence to move inwards towards the vessel), so moves a spring supported
face piece b2 by means of a lever y¹ (and, if need be, a further intermediate rod u¹ c²),
that the same is made capable of bringing the hand lever q for the driving engine
of the windlass almost at the "stop" position, when this lever is in such a position
that the driving engine winds up the rope g.
4. In combination with a windlass as in Claim 1, a piston f (connected with the
slide p) for the steam engine, said piston being continuously under pressure of live
steam, and operating to bring the hand valve p immediately to the position of
completely stopping the engine, when the lever is not under the control of the man
at the windlass.
5. In combination with the reversing engine for driving the windlass of Claim 1, a
valve g², this valve operating to admit atmospheric air to the port of the engine
corresponding to its direction of rotation, & so forming an air cushion in front of the
piston, to prevent the further rotation of the engine, when turned in the undesired
direction by the weight of the boat, or after the shifting of the lever p.
6. The modification of the windlass described in Claim 1, by making the rods e
in the form of racks, and coupling and releasing the wheel e³ working the racks
at the proper moment by a clutch and a lever and shaft « automatically operated
by the rods e.