IMPROVEMENTS IN SHIPS' LOGS
Year: 1884

page_text: I, ALEXANDER MELVILLE CLARK, of the firm of A. M. and Wm. Clark, of
53, Chancery Lane, in the County of Middlesex, Fellow of the Institute of Patent
Agents, do hereby declare the nature of the said Invention for "IMPROVEMENTS IN
SHIPS' LOGS" & communication to me from abroad by David Carroll of Union City,
in the county of Erie, and state of Pennsylvania, United States of America to be
as follows:
This invention relates to an improved nautical log for indicating the headway
and leeway motions of the ship by means of pointers and dials, the pointers being
worked by means of screw vaned wheels hereafter designated rotators let down into
the water through a well in the ship.
The essential features of the invention consist of a contrivance for setting the
rotators in the line of the well for passing them through a well of small size and
afterwards swinging them up horizontally and into position in advance of the
supporting rod to enable the water to act on them in advance of any disturbing
effect of the supporting rod.
Also of a contrivance of two rotators placed at an angle to the ships' keel in such
manner that both run alike when the ship advances without drifting, and indicate
the advance by the sum of their revolutions, but vary when the ship drifts and
indicate the same by the difference of their revolutions; and the invention also
consists in certain details of apparatus all as hereinafter fully described.
In this improvement, I arrange two vaned wheels or rotators, one above another
on a vertical support extending down through the well in the ships' bottom, the
spindles of said rotators being mounted in hollow arms pivoted to the support and
attached to a vertical rack rod extending up through the well for shifting the
rotator bearing arms up into the horizontal position and down into a vertical
position and also for raising the rotators up into the well when out of use and
lowering them when they are to be used. The connection of the rack rod with the
bearing arms is such that in raising the rotators into the well, the first effect is to
swing the rotator bearing arms down into the vertical position so that the rotators
will rise in a well of no larger diameter than that of the rotators and the next
result is the raising of the rotators in the well.
When the pinion is turned in the other direction for lowering the rotators, the
weight of the supporting stock and rotators will carry all down together until the
descent of the stock is arrested when the further operation of the pinion will cause
the rotator bearings to swing up into horizontal position for use.
Above the upper rotator bearing the stock consists of a tube up which two small
tubes extend for enclosing wire spindles which gear with the rotators respectively
by worm gear for transmitting the motion of the rotators to the indicators.

page_text: These tubes serve to conduct oil down for lubricating the rotator spindles and
worm gear the tubes being sufficiently extended above the water level to contain
oil columns of sufficient length to force out the water and lubricate the working
parts.
The rotators are arranged obliquely to the line of the keel and symmetrically or
at equal angles on opposite sides of the same, so that both will revolve at the same
speed when the ship is advancing without falling off either way, but if the ship
falls off either way one will run slower than the other, the cause of which will be
readily understood when it is considered that if one rotator were on the line of the
keel and the other at a right angle to it the latter would not revolve at all when
the ship goes straight ahead and should the ship drift directly at right angles to
the keel the rotator set in that position would revolve and the other would not.
The rotators thus arranged are geared to the leeway indicator train by right and
left worm gear and a compound wheel consisting of a pair of bevel pinions gearing
with an intermediate bevel pinion carried by a worm disc gearing with a wheel on
the same arbor with a friction roller that runs against a friction disc, on the arbor
of the unit hand which moves over the leeway dial, so that the respective rotators
drive in opposite directions; consequently when they are both running at the same
speed their effect on the pointers of the indicator will be neutralized by the
intermediate bevel pinion simply turning on its axis without giving any rotation
to the worm disc, but when the rotators turn at different speeds the worm disc will
receive a differential motion in one direction or the other. Hence when the ship.
falls to leeward the pointers of the leeway dial will bo turned forward or backward
as she falls to port or starboard, and indicate the same. The rotators are similarly
geared to the headway indicator train except that both drive on it in the same
instead of in opposite directions as before, the worm gears being both pitched aliko
so that when both rotators run at like speed the headway indicator will indicate the
maximum speed of the rotators, but should one rotator run slower the indicator
will fall short of the maximun speed to the extent of the difference of the speeds
of the two rotators, which will be the amount of the leeway drift indicated on the
lower dial. In this statement of the case it is assumed that the leeway is in direct
proportion as the difference of the speed of the two rotators, but practically it is
five times the difference and therefore the differential worm disc of the leeway
indicator is constructed with five threads to the turn, to speed up the leeway
indicator to that extent faster than the other indicator whose worm disc is
constructed with but one thread to the turn.
The wire spindles which transmit the motion of the rotators to the indicators
extend above the upper indicator where they connect with each other by a length
of flexible spindle and a compound or differential wheel consisting of two bevel
pinions and an intermediate pinion carried by a disc, the object of which is to
provide a ready means of testing the accuracy with which the rotators are adjusted
with reference to their inclination to the keel when the instrument is put in the
vessel. The friction rollers of the indicator trains are fitted to their spindles so as
to slide along them towards and from the centre of the friction disc for adjusting
the speed of the clock trains and they are arranged between the prongs of a yoke
fitted on an adjusting screw for shifting them. The spindles of said rollers are
mounted in pivoted frames and pressed by a spring against the friction discs to
produce the requisite friction for driving the indicator trains. The leeway
indicator train comprises only the means for working the arbors for two hands to
count one hundred, above which the record must be kept by tally, but the train
for the headway indicator turns three hands for counting up to one thousand.
ALL
P 1004

page_text: I, ALEXANDER MELVILLE CLARK, of the firm of A. M. and Wm. Clark, of
53, Chancery Lane, in the County of Middlesex, Fellow of the Institute of Patent
Agents, do hereby declare the nature of the said Invention for " IMPROVEMENTS IN
SHIPS LOGS," (a communication to me from abroad by David Carroll of Union City
in the County of Eric, and State of Pennsylvania, United States of America,) and
in what manner the same is to be performed, to be particularly described and
ascertained in and by the following statement:-
This Invention relates to an improved nautical log for indicating the headway
and leeway motions of the ship by means of pointers and dials the pointers being
worked by means of screws or vaned wheels hereafter designated rotators let down
into the water through a well in the ship.
The essential features of the invention consist of a contrivance for setting the
rotators in the line of the well for passing them through a well of small size and
afterwards swinging them up horizontally and into position in advance of the
supporting rod to enable the water to act on them in advance of any disturbing
effect of the supporting rod.
Also of a contrivance of two rotators placed at an angle to the ships keel in such
manner that both run aliko when the ship advances without drifting, and indicato
the advance by the maximum speed of the wheels but vary when the ship drifts,
and indicate the same by the difference of their revolutions, and the invention also
consists of certain details of apparatus all as hereinafter fully described.
Reference is to be had to the accompanying drawings forming part of this
specification in which similar letters of reference indicate corresponding parts in all
the figures.
Figure 1 is a front elevation of the indicator mechanism with the front of the
enclosing case and part of the dials removed to show the said mechanism clearly.
Figure 2 is a horizontal section of one of the rotators and top view of the other
as when adjusted for use, also a section of the stock by which the rotators are
suspended, and of the gear connecting them with the indicator mechanism.
Figure 3 is a side elevation of the rotators as adjusted below the ships bottom
for use and a sectional elevation of the suspending stock and
Figure 4 is a detail of the leeway indicator.
In this improvement is arranged two vaned wheels or rotators a and b one above
another on a vertical support c extending down through the well d in the ships
bottom e the spindles of said rotators being mounted in hollow arms fattached to
support c by pivots g, and also attached to a vertical adjusting rod h extending up
through the well and having a rack i, gearing with a pinion; for shifting the
rotator bearing arms up into the horizontal position represented in full lines
figures 2 and 3 and down into the position represented in dotted lines figure 3 and
also for raising the rotators up into the well when out of use and lowering them
when they are to be used. The rod h is pivoted at k to the bearing discs of the
arms eccentrically to the pivots g so that when the pinion j is turned with a
crank or other means the first effect is to swing the bearing arms f down into the
vertical positions indicated by dotted lines so that the rotators will rise in a well
of no larger diameter than that of the rotators and the next result is the raising of
the rotators in the well.
When the pinion is turned in the other direction for lowering the rotators the
weight of the supporting stock and rotators will carry all down together until a

page_text: cap on the upper end of the stock or any other means for stopping the descent of
the same comes to rest on any suitable stop device then the further operation of
the pinion will cause the arms f to swing up into horizontal position for use.
Above the upper arm f the stock c consists of a tube up which two small
tubes m extend for enclosing the wires n which gear with the rotators a b
respectively by the wheels o and worms p for transmitting the motion of the
rotators to the indicators.
These tubes m are tapped into the upper end of the lower part of the stock o
which is bored therefrom to the chamber q where the wires connect with their
respective wheels o the object of the tubes m being to conduct oil down to the
ohamber for lubricating the rotator spindles and gears, the oil being poured into
the tubes at the upper end which tubes are sufficiently extended above the water
level to contain oil columns of sufficient length to force out the water and lubricato
the working parts.
When the rotators a b shift down to the dotted position for being raised up in.
the well the worms p disconnect from the gears o and they engage with said wheels
again when raised up.
The rotators ab are arranged obliquely to the line of the keel s and symmetrically
or at equal angles on opposite sides of the same so that both will revolve at the
same speed when the ship is advancing without falling off either way, but if the
ship falls off either way one will run slower than the other, the cause of which will
be readily understood when it is considered that if one rotator were on the line of
the keel and the other at a right angle to it the latter would not revolve at all
when the ship goes straight ahead and should the ship drift directly at right angles
to the keel the rotator set in that position would revolve and the other would not.
The rotators are also constructed in the form of their arms at t to enable them
to run with as little obstruction as possible when receiving the water obliquely.
The rotators a b thus arranged are geared to the leeway indicator train which is
the lower indicator of the drawing by the right and left worms u, worm wheels v
and the compound wheel consisting of the three bevel pinions wand the worm
disc x, said disc gearing with the wheel y which turns the small friction roller
that runs against the friction dise a' on the arbor b' of the unit hand which moves
over the leeway dial c¹ so that it will be seen that the respective rotators drive in
opposite directions; consequently when they are both running at the same speed
their effect on the pointers of the indicator will be neutralized by the intermediate
bevel pinion w simply turning on its axis in disc without giving any rotation to
the disc but when said rotators ab turn at different speeds the disc x will receive
a differential motion in one direction or the other according as one rotator over-
runs the other or to the extent of the difference between the motions of the two
rotators a b. Hence when the ship falls to leeward the pointers of the leeway dial
will be turned forward or backward as she falls to port or starboard, and indicate
the same.
The rotators ab are geared to the upper headway indicator train so
that both drive on it in the same direction by the worms d¹ both pitched alike,
wheels e¹ and the compound wheel consisting of the three bevel pinions f' and
worm discs g¹ said disc gearing with the indicator train similar to that of the
leeway indicator and consisting of a wheel y friction pinion and friction disc a'
said disc being on the post h¹ of the unit hand of the indicator for the headway
movement of the vessel from which it will be seen that when both rotators a b
run at like speed the headway indicator will indicate the maximum speed of the
rotators but should one rotator run slower the indicator will fall short of the
maximum speed to the extent of the difference of the speeds of the two rotators
which will be the amount of the leeway drift, indicated on the lower dial. In this
statement of the case it is assumed that the leeway is in direct proportion as the
difference of the speed of the two rotators but practically it is five times the
difference and therefore the disc x of the leeway indicator is constructed with five
threads to the turn, to speed up the leeway indicator to that extent faster than the
other indicator whose worm disc g¹ is constructed with but one thread to the turn.

page_text: To ascertain the ships position measure on the chart from the starting point in
the line the ship is held on by the compass, the distance indicated by the headway
indicator from the point thus reached measure to leeward the distance indicated
by the leeway indicator and thus arrive at the ships position. Should the wind
change and cause the ship to fall to leeward in the reverse direction, the pointer of
the leeway dial will run back to zero when the ship returns to the headway line
on which she started.
The wires n extend above the upper indicator where they connect with each
other by the flexible section and the compound wheel consisting of the bevel
pinions and the disc the object of which is to provide a ready means of testing
the accuracy with which the rotators are adjusted with reference to their inclination
to the keel when the instrument is put in the vessel which may be done as
follows: Put the vessel on a straight line with the wind so that she will not fall
off or make leeway, by a steam tug if a sailing vessel, then watch the middle
bovel wheel of the compound wheel which should stand at rest if the
rotators a bare set rightly, but should said wheel k¹ turn slightly the support c of
the rotators a b must be turned to right or left to shift said rotators until said
middle wheel ceases to turn on its own axis when the rotators a b will be right.
The said support c will have any suitable cap lever or other device at the upper
end for so shifting it and also for holding said support when adjusted. The friction
rollers of the indicator trains are fitted to their spindles so as to slide along them
towards and from the centre of the discs a¹ for adjusting the speed of the clock
trains and they are arranged between the prongs m¹ of a yoke fitted on an adjusting
screw n¹ for shifting them. The spindles o' of said rollers are mounted in frames pl
suspended on rods q' and fitted with a spring a¹ that presses the roller against the
disc to produce the requisite friction for driving the indicator trains. The leeway
indicator train comprises only the means for working the arbors b¹ and t¹ for two
hands to count one hundred, above which the record must be kept by tally, but
the train for the headway indicator turns three hands for counting up to one
thousand.
It is to be understood that the rotators ab and their support c are so arranged
that they swing up to their working position in the forward direction so as to get
the best effects of the water in advance of the disturbing influence of the support c
the supporting arms and the adjusting rod h.
The arrangement of the two rotators so that both shall be constantly in motion
is better than an arrangement in which the leeway rotator is so placed that it does
not revolve when the ship advances without leeway because in that case the
rotator is not so sensitive and will not run with the leeway movement until the
movement is of considerable extent while in this arrangement the rotators are
sensitive to the slightest change and indicate the same promptly.
Having now particularly described and ascertained the nature of the said
invention and in what manner the same is to be performed I declare that what
I claim is :-
1. In a nautical log two rotators ab arranged obliquely to and on opposite
sides of the keel and geared reversely to the leeway indicator and directly to the
headway indicator by combination or differential wheels substantially as described.
2. In a nautical log the combination of two continuously revolving rotators
arranged to run alike by the headway of the vessel and to vary in speed by the
leeway of said vessel, a headway indicator geared with said rotators differentially
and indicating the headway of the vessel and a leeway indicator also geared
differentially with said wheels and indicating the difference of the speeds of said
wheels substantially as described.
3. The combination in a nautical log of two rotators ab arranged obliquely to
and on opposite sides of the keel, and geared by wires n right and left worms,
wheels and compound wheel wx, with the leeway indicator train substantially
as described,

page_text: 4. The combination in a nautical log of two rotators ab arranged obliquely to
and on opposite sides of the keel, and geared by wires n worms d¹ of like pitch,
wheels e and compound wheel f¹ g¹ with the headway indicator train substantially
as described.
5. The combination in a nautical log of two rotators a b arranged obliquely to
and on opposite sides of the keel, and geared by wires n, right and left worms u,
wheels v, and compound wheels wx with the leeway indicator, also geared by said
wires n, worms d³, of like pitch, wheels e¹ and compound wheels f' g¹ with the
headway indicator train substantially as described.
6. In a nautical log consisting of two rotators a b arranged obliquely to and
on opposite sides of the keel, a headway indicator and a leeway indicator geared
together by the wires n and differential mechanism as described, the said wires n,
coupled above the indicators by the flexible sections j¹ and compound wheels V
to form an indicator to adjust the rotators a b substantially as specified.
7. In a nautical log having rotators a b arranged on a supporting stock c fitted
in a well & through the bottom of the ship, said rotators connected by arm fand
pivots g with the stock and provided with means for shifting them into the line of
the stock for drawing them into the well and also for shifting them into and
maintaining them in the working position substantially as described.
8. In a nautical log having rotators ab mounted on a stock c projecting from
the ship into the water said rotators arranged on said stock to project forward of
the same to receive the-water in advance of_and_undisturbed by the influence of
said stock on the water substantially as described.
9. The combination of the shifting rod h with the supporting arms f pivoted to
the stock c substantially as described.
10. The shifting rod h connected with the supporting arm pivoted to the
stock c extended up through the well and geared by a toothed rack i with a
pinion j for adjusting the rotators thereby substantially as described.
11. The tubes m in combination with the wires n stock c and the wheel gears op
for lubricating the same substantially as described.
A
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