An Improved Log and Current Meter.
Year: 1889

page_text: Date of Application, 10th Apr., 1889
Complete Specification Left, 8th Feb., 1890-Accepted 8th Mar., 1890
PROVISIONAL SPECIFICATION.
An Improved Log and Current Meter.
I DUNCAN MCGREGOR Junior. Nautical Instrument Maker residing at 13 Knowe
Terrace Pollokshields, Glasgow in the County of Lanark Scotland do hereby declare
the nature of this invention to be as follows:-
This Log or Meter is an improved instrument for recording the distance a vessel
travels through the water or it may be used for ascertaining the speed of currents of
water or other the like purposes.
.
The movement or wheelwork is contained in a strong metal case which by suitable
fittings accommodates itself to and neutralises any motion due to the rolling or
pitching of the vessel.
Instead of using with this instrument a dial or a series of dials over which
indicating hands travel round I have a series of small openings in the case one or more
in number by preference I use five. Behind these openings circular drums revolve
each drum being marked with numbers 0 to 9 inclusive. The first drum makes one
complete revolution in one mile, the second revolves once in ten miles, the third once in.
a hundred miles and so on according to the number of miles it is deemed necessary to
cause the log to indicate, one figure at a time being visible through the openings.
These drums are geared into each other by means of wheels attached to same and
pinions having the requisite number of teeth to give the desired motions. Each of
the pinions has every alternate tooth removed to the extent of half its thickness, the
effect of this is one half of the pinion works into one drum and the other half of
the pinion having double the number of teeth, works into the other and adjoining
drum. The pinions work upon one or more spindles or arbors which may be made
moveable so that the drums may be unlocked and set to zero when desired. By
another method thin metallic rims with the figures upon them may be sprung on to
the drums and shifted round by hand when requiring to be set. Connected to the
drums and their gearing is another series of wheels and pinions terminating in a spindle
which projects beyond the case of the instrument. To this spindle is attached a line
or rope of suitable length having at its other end a rotator of wood brass, or
other suitable material, fitted with fans, blades or vanes set at the required angle.
When in action the rotator is towed in the sea behind the ship. The speed of
the vessel through the water gives the rotator a certain movement which is conveyed
to the mechanism on board. The towing line may be made of one or more metallic
wires of suitable strength insulated or protected by gutta percha or other covering,
or twisted or plaited wires may be used with or without any covering or protection.
To the recording instrument on board I also fit an electrical connection, one of
the wheels is so arranged that a contact, is made as often as desired by preference,
I use ten contacts in each mile. Each contact sends the current to a dial or a series
of dials or plates and by mechanism actuates a hand or hands causing them to indicate
upon the dial or dials, the distance run as shown by the recording log itself. This
electrical tell tale which may be fitted with an audible signal if desired, can be used
in any convenient part of the ship such as bridge, wheel house chart room captains
room.and connected electrically with the log itself which may be used on the taffrail
or other suitable part of the vessel.
The Log may be used without the electrical tell tale attached.

page_text: COMPLETE
SPECIFICATION.
An Improved Log and Current Meter.
I, DUNCAN MCGREGOR, Junior, Nautical Instrument Maker, residing at 13 Knowe
Terrace, Pollokshields, Glasgow, in the County of Lanark, Scotland, 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 in writing,
reference being had to the accompanying Sheet of Drawings, and to the letters and
figures marked thereon, that is to say :-
This Log or Meter is an improved instrument for recording the distance a vessel
travels through the water, or it may be used for ascertaining the speed of currents of
water or other like purposes. The movement or wheel work is contained in a strong
metal case which by suitable fittings accommodates itself to and neutralizes any motion
due to the rolling or pitching of the vessel. Instead of using with this Instrument
as heretofore a dial, or a series of dials over which indicating hands travel round, I
have a series of small openings in the case, one or more in number by preference I
use five.
Behind these openings circular drums revolve each drum being marked
with numbers 0 to 9 inclusive. The first drum makes a complete revolution in one
mile, the second revolves once in ten miles, the third once in a hundred miles, and
so on according to the number of miles it is deemed necessary to cause the log to
indicate, one figure at a time being visible on each drum through the openings. These
drums are geared into each other by means of wheels attached to same and pinions
having the requisite number of teeth to give the desired motions. Each of the pinions
has every alternate tooth removed to the extent of half its thickness the effect of this
is one half of the pinion works into one drum and the other half of the pinion
having double the number of teeth works into the other and adjoining drum the
pinions work upon one or more spindles or arbors which may be moveable so that
the drums may be unlocked and set to zero when desired.
By another method these metallic rims with the figures upon them may be spring
on to the drums and shifted round by hand when requiring to be set. Connected to
the drums and their gearing is another series of wheels and pinions terminating in
a spindle which projects beyond the case of the instrument, to this spindle is attached
a line or rope of suitable length having at its other end a rotator of wood brass or
other suitable material fitted with fans, blades, or vanes set at required angles.
When in action the rotator is towed in the sea behind the vessel. The speed of
the vessel through the water gives the rotator a certain movement which is conveyed
to the mechanism on board.
The towing line may be made of one or more metallic wires of suitable strength
insulated or protected by gutta-percha or other covering, or twisted or plaited wires
may be used with or without any covering or protection. To the recording instrument
on board I also fit an electrical connection, one of the wheels is so arranged that a
contact is made as often as desired, by preference I use ten contacts in each mile,
each contact sends the current to a dial or a series of dials or plates and by
mechanism actuates a hand or hands causing them to indicate upon the dial or
-dials the distance run as shown by the recording log itself. This electrical tell-tale
which may be fitted with an audible signal if desired can be used in any convenient
part of the ship such as the bridge, wheelhouse, chart room, captains room and con-
nected electrically with the log itself which may be used on the taffrail or other suitable
part of the vessel. The log may be used without the electrical tell-tale attached.
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 an
explanatory sheet of Drawings in which the same reference letters are used to indicate
corresponding parts in all the figures where shown.
Figure 1 is a plan view with the top cover of the containing case opened out,
showing my new or improved log or speed indicating drum mechanism for indicating
the speed and distance traversed by the vessel from any given starting time; and

page_text: Fig. 2 is a sectional end view of same taken near the irregular line 1-1, Figure 1, and
showing the swivelling carrying stand B, B1, B2, dotted in. While Figure 3 shows side
and sectional edge views respectively of one of the set of number indicating drums or
discs a and its moving wheels a¹, a. Figure 4 shows a plan of the recording log
Figures 1 and 2, to a smaller scale, with the lid closed and the holos showing the
numbers on the drums as brought to view. Figure 5 is a back view or elevation without
its enclosing case of one arrangement of tell-tale dial indicating mechanism and escape-
ment and electrical connections to transmit from the recording log mechanism to and
indicate by these dials and pointers placed at the bridge or other convenient part of the
ship, the speed of and distance traversed by the vessel. Figure 6 is a plan view of the
mechanism, and Figure 7 a front view showing the dials and pointers both corre-
sponding to Figure 5. Referring to the improved recording log part of this Invention
shown in Figures 1 to 4, the whole recording mechanism and improved gearing
connections are contained within a strong protecting brass or other box A, within an
enclosing lid A', hinged at one side A" on top of box A, to protect the mechanisin.
The lid A' is open in the centre at top but has a closing in glass and plate mounted in
it, with small holes A* over the centre of the numbering discs a to show the figures as
brought to view. As shown dotted in Figure 2 the whole case A is mounted by side
journal brackets A³ projecting up from its bottom plate A having its trunnions at B
in a swivelling bow bracket B' B mounted by its centre spindle and collar B2 over a
plate B secured on any suitable frame or rail of the vessel as on the taffrail, a thumb
screw B in the plate B preventing the swivelling collar and spindle B2 of the gimbal
frame B, B, from rising out of the plate. The indicating mechanism consists of a
set of five numbering drums or discs a, but they might be more or less, each numbered
on the edge 0 to 9 consecutively in the direction the discs are turned, and as shown
in the detailed views Figure 3. Each disc a has secured to it at its centre a driving
toothed wheel a' and a disc a'. with one toothed recess a¹¹ in it which each revolution
turns the next numbering disc in succession one division and number round in the
same direction as will hereinafter be described. All these numbering discs a shown at
1, 2, 3, 4, 5, Figure 1, are mounted loose on a fixed spindle C carried at its two ends
in the bracket standards C₁ C" secured to the bottom plate A2 of the box A. A bevel
wheel e with a first disc a secured on it, are mounted loose on the spindle C, close up
to the wheel a¹ of the first numbering disc a, so that each revolution of this bevel
wheel c and disc a³ by its recess tooth a¹ as it comes round, actuates the first pinion 6
to turn it to the extent of one tooth, which pinion b turns the wheel a¹ of the first
numbering disc a to the extent of two teeth, as this pinion has the half of every
alternate tooth cut away on the one side which works into the disc a³. Thus the pinion b
has four teeth working into the disc a³ and eight teeth working into the wheel a¹ which
bas twenty teeth, thus turning the disc a a tenth of a revolution each revolution of the
wheel c and disc a³. The front pinion b and other four similar pinions are all mounted
loose on a spindle D fixed in the top of a rocking frame D¹, fulcrumed to brackets
in the bottom of the box A2, and so as to gear into the subsequent disc a and spur
wheel a¹ of each succeeding pair of numbering wheels 1 to 5, thus turning each of
these numbering discs one division each revolution of its preceding disc. The first disc
number 1, indicates tenths or decimals of a mile, the second units or miles, the third
tens of miles, the fourth hundreds and the fifth thousands of miles.
α
The frame D, D₁, is made to oscillate out with the pinions b on it, so that these
pinions may be all turned round to bring the numbering discs a, 1 to 5, back to zero
when desired, and the pinions be then oscillated into gear with their respective
actuating toothed wheels and discs a¹, a². This rocking frame D, D¹, is shown as
locked with the pinions in gear, in Figures 1 and 2, by a slide locking bar E E' carried
in slide guides E, secured to the side of the box A, the projecting lockers E' of this
bar coming against the top of the oscillating arms D', when shifted in one direction by
the vertical hand lever E' fulcrumed near the bottom A' of the box A and having its
top end passing through a slot in the centre of the bar E, and when shifted in the
other direction relieve the rocking frame so that it may be drawn back to change the
wheels as described. This hand lever E' may also luck a lateral pin E' in the lower

page_text: part of the rocking frame when shifted to the right as shown in Figure 1, in addition
to the locking projections E¹ on the bar E at top. Or this locking bar E E¹ may be
used by itself with a hand knob for shifting it, or the lever with its pin might alone
be used. The lever E would be locked at its upper end E by a slot A in the under
rim of the lid A¹ of the box A, when the lid is folded down, and this lid may be secured
from the outside by an ordinary lock and key to prevent tampering with the internal
mechanism when so desired.
The driving mechanism consists of a bevel or mitre wheel c¹ gearing into the bevel
wheel c before mentioned mounted on a transverse spindle in bearing brackets C
near its ends, actuated by a spur wheel c" near its other end, gearing into a pinion c
mounted on one end of a spindle c³ rotating in the upper back end of the same two
brackets C. This spindle has secured on it a screw wheel d' gearing into a
screw d on the inner end of the first motion spindle d, carried at its inner end on the
bracket C³, and in a journal boss C, on the rear end of the box A, preferably with a
disc collar e and three antifriction rollers e' between this collar e and the end of the
box A, the rollers e¹ being carried on journal studs ell on the end of a tripod eye
mounted loose on the spindle d. This first motion spindle d of the mechanism is
actuated from the outside, by a ring eye d³ screwed or otherwise secured on the outer end
of it and attached by an eye or Shook or otherwise to the rotating tow line fof any of
the ordinary screw vane rotators or logs as indicated at f¹. The arrows on the Figures
indicate the direction of rotation of the several wheels and mechanism particularly in
Figures 1 and 5.
A further improvement of this invention consists in making this recording log
mechanism also actuate a tell-tale indicator when that is desired, such as that shown
with rotating hands and dials in Figures to 7, in the chart room or other convenient
part of the vessel by an arrangement of electric make and break contact and escape-
ment mechanism. This is effected primarily by securing a rotating lever or spring
make and break contact switch g on the one end of the spindle within the box A so
that each time it came round it would make contact with two spring or plate
terminals g¹, g, of the line wires indicated at + and -, between the battery and an
electro double bobbin magnet H, H, ranged near one end of the indicating mechanism
shown in Figures 5 and 6, wherever that was placed. This mechanism is shown as
having five indicating spindles and pointers numbered 1, 2, 3, 4, 5, the first indicating.
decimals of a mile, the second units, the third tens, the fourth hundreds, and the fifth
thousands of miles. These spindles 1 to 5 with driving pinions and wheels p, p, on
them are all mounted to rotate in the sides of a metal frame F, and have four inter-
mediate spindles 2¹, 31, 4, 5¹ similarly mounted in the frames F with transmitting
reducing wheels and pinions p³, p³, on them, the number of teeth in the pinions and
wheels being such that as the first spindle and pointer of the first dial makes one
revolution, it makes the spindle and pointer of the second dial 2 go a tenth of a revolu-
tion, and as this makes one revolution it makes the next go a tenth of a revolution,
and so on decimally the pointers all turning in the same direction as indicated by the
arrows in Figure 7. Each pointer is fixed on the outer end of its spindle to turn by
stiff friction, like the hands of a clock so as to be able to set them to zero when desired.
The spindle 1 of the first index and dial has mounted on its outer end a ten toothed
escapement wheel i, actuated by a double pallet bellcrank oscillating escapement
lever fulcrumed on a stud at 11 in the side of the frame F, a pin in the back
arm of the escapement lever, taking into a fork or slot in the arm of an actuating
lever,, fulcrumed on a stud at secured to a bracket F1 at one end of the frame F.
This lever is actuated in one direction by a spiral or other spring j attached to the
arın of the lever and to a fixed stud at j¹. While it is actuated in the other
direction by the armature h of the electro magnet H, attached by a guide spindle h¹
to the other arm of the lever 3,, all so that each time the first spindle c
and the switch g on it of the log mechanism Figure 1 makes one revolution and
completes the circuit through the battery not shown in the Drawings, and the
electro magnet H, it pulls the armature h and oscillates the lever i and
escapement lever i " to the position indicated in dotted lines in Figure 5, and as

page_text: soon as the switch g passes the make and break contact springs g¹, g, and breaks
the circuit, the spring; comes into action and brings back the lever and escapement
to the position shown in sharp lines in Figure 5 these two movements of the escape-
ment levers turning the escapement wheel i and the first spindle and pointer 1 one
tooth or tenth of a revolution in the direction of the arrows in Figures 5 and 7. The
escapement wheel i would have a light pressing or friction spring or other equivalent
as shown at i to prevent it shaking or moving back during the action of the pallets ¹¹
of the escapement; and the armature h might be guided by its spindle in a bracket
or other equivalent, as indicated at h' secured to the frame F, and the whole arrange-
ment of mechanism with its electro magnet H might be fitted in a containing and
protecting box with a glass lid, not shown in the Drawings to be secured to the wall
of the chart room or other part of the vessel desired, with any ordinary_small battery
fitted in any suitable box placed conveniently near the electro magnet H H to excite
it. Although a double pallet lever escapement has been shown and described for
actuating the electric tell-tale recorder figures 5 to 7, by and at a distance from the
log recorder figure 1, other equivalent escapements may be employed such as the
single pulling pawl arrangement used in electric clocks. And although the spindles
of the distance electric indicators have been shown and described as actuating pointers
it is to be understood that they might actuate the figured dials or discs with the
numbers on their edges, and have the pointers fixed or stationary instead of rotating.
Or otherwise instead of having the discs or drums on different axes all the drums
with the numbers on their edges might be mounted longitudinally in line on a fixed
spindle as in Figure 1, the escapement wheel being actuated loose on it in the same
manner as the bevel wheel c in Figure 1 actuates the disc wheel a³ of the whole set
of numbering drums, this electric arrangement of indicators being otherwise as in
Figures 1 to 4. The electro magnet H of the tell-tale mechanism may be made to
sound a bell, gong or other audible signal when set in action by the log mechanism
Figure 1 by making its armature h actuate a light spring lever or other equivalent to
strike the bell or gong while it is vibrating and thus give notice to the attendants in
the chart room or other part of the vessel where the electric recording mechanism
is placed that the log mechanism is in action at the taffrail or deck where it is placed.
The make and break contacts 9, 91, 9", in the log box A would be covered in for protec-
tion to ensure contact; and the covered insulated wires x and-from these contacts coming
through the sides of the box would be left sufficiently loose to allow the box to
oscillate freely on its gimbals to the motion of the screw rotator or log in the
water.
Having now particularly described and ascertained the nature of my said inven-
tion, and in what manner the same is to be performed I declare that what I
claim is :-
First. A recording log, for indicating the speed and distance of a ship's motion or
the velocity of a water current comprising the combination of a speed counter having
a series of indicating edge numbered drums or wheels directly connected to wheel
gearing which receive motion from a revolving spindle attached to a tow rope and
propeller or motor rotated by the motion of the vessel or current, substantially as
herein described in reference to and shown in Figures 1 to 4 of the accompanying
Drawings.
Second. In combination with the mechanism of the above claimed recording log,
an electrical make and break contact mechanism actuating speed and distance
indicating dials or drums substantially as herein described in reference to and shown
in Figures 5, 6, and 7 of the accompanying Drawings.
D11 D1000
W. R. M. THOMSON & Co.,
Agents.