Improvements in Ship-log Apparatus.
Year: 1897

page_text: Date of Application, 19th May, 1897
Complete Specification Left, 19th Feb., 1898- Accepted, 19th May, 1898
Improvements in Ship-log Apparatus.
I, WILLIAM DUNLEY OWEN, of 136, Bensham Lane, Thornton Heath, in the
County of Surrey, Clerk, do hereby declare the nature of this invention to be as
follows:-
This invention relates to ship-log apparatus of the kind in which the indicating
mechanism is fixed on or to the taffrail or other fixed part of the vessel while the
rotator when in use is in the water.
The object of this invention is to provide the indicating mechanism of log-
apparatus of the kind above referred to with means whereby an audible or other
signal will be given at intervals or continuously in the chart house, on the bridge
or in any other suitable part of the vessel so as to indicate the working of the log;
and furthermore to provide means whereby the indications on the dial can be
read off in the dark.
To carry out the first part of my invention I connect the dial pointer or the
wheel train which actuates it with the chart house, bridge, or other part by means
of electrical conducting wires connected to a suitable battery. In the circuit a bell
may be arranged in the chart house, bridge or other part of the vessel so as to
ring when the pointer reaches given positions. On the chart house or other part
of the vessel may be fitted with duplicate dial and pointer mechanism operated
electrically so as to reproduce the movements of the pointer of the indicating
mechanism of the log.
To carry out the second part of my invention I provide a chamber in rear of the
indicating dial on the log, and in this chamber I fix an incandescent electric
lamp connected to a suitable electrical circuit and provide means for switching
the current on or off as required. The dial is made of a semi-transparent material
so that the graduations thereon and the position of the pointer can be easily read
off in the dark.
I, WILLIAM DUNLEY OWEN, of 136, Bensham Lane, Thornton Heath, in the
County of Surrey, Commercial Clerk, do hereby declare the nature of this invention
and in what manner the same is to be performed, to be particularly described and
CD 871

page_text: ascertained in and by the following statement, reference being had to the accom-
panying drawings and to the letters and figures marked thereon, that is to say:-
This invention relates to ship-log apparatus of the kind in which the indicating
mechanism is secured on or to the tafirail, or other fixed part of the ship, while the
rotator, when in use, is in the water; and the object of my invention is to render
the dial of the indicating mechanism visible in the dark, without the use of a
lantern and, when desired, to enable the readings of such dial to be ascertained
in the charthouse, or on the bridge, or in any other desired part of the ship.
And in order that my said invention may be readily understood, I will describe
the same fully with reference to the accompanying drawings, wherein:
Fig. 1 is a front view of the indicator of a ship-log apparatus known as Cherub"
log, and embodying part of my improvements.
Fig. 2 is a fragmentary side elevation of the same.
Fig. 3 is a similar view to Fig. 2, but partly in section.
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Fig. 4 is an underside view of the dial of the indicator; together with the means
for rendering the same luminous.
Fig. 5 is a detail.
Fig. 6 is a diagrammatic view of a suitable arrangement for use in connection
with the indicating mechanism, and
Fig. 7 is a detail of Fig. 6.
In applying my improvements to the above type of apparatus, I neither alter
nor interfere with the indicating mechanism ordinarily employed, and which
therefore needs no special description.
For the purpose of my invention, I provide the casing a of an ordinary ship-log
apparatus with a dial 6 of translucent, or semi-transparent, material, and I mount
such dial at a sufficient distance from the usual working mechanism to allow of an.
electric incandescent lamp c, with its conducting wires cc, being placed behind
it in such a manner as to illuminate the dial when desired..
The said lamp, which is preferably of flattened form, as shewn, to economise
space, is caried by an arm or bracket d, and is connected to a push or switch e
arranged on the outside of the casing a. By depressing the push, the electrio
circuit is completed and the lamp is caused to glow, so illuminating the dial, and
permitting the position of the hand or pointer f thereon, to be readily ascertained
in the dark, and the readings to be taken. If, however, it be desired to keep the
dial illuminated for any length of time, or during foggy weather, I employ a spring
arm e' which is caused to bear on the push or switch and hold it down so keeping
the circuit closed and the lamp aglow.
A reflector may be arranged behind the lamp.
"Cherub"
When applying my invention to an existing log apparatus, say to a
log, I mount the translucent dial, and its glow lamp, together with the push or
switch, in a separate chamber (not shewn) and connect such chamber, in any con-
venient manner, to the casing a of the indicating mechanism. I then extend the
spindle or arbor h, carrying the hand or pointer f, so as to cause it to project
through the translucent dial. This may be effected by providing an additional
spindle h¹ having a split socket h³ adapted to fit on the end of the existing spindle
or arbor and carry the said hand or pointer. Such an arrangement is clearly
shewn in Fig. 5.
Where a second hand or pointer, such as f¹, is used for marking the knots, a
similar arrangement to that above described for extending its arbor or spindle is
employed.
It is obvious that by means of my invention the readings of the log apparatus"
can, at any moment, be ascertained in the dark, without requiring the use of a
lantern, or other extranous means.
To enable the said readings to be perceived at any other part of the ship, as for
instance in the charthouse, or on the bridge, I provide indicating apparatus com-
prising a dial i (which may also be translucent and have a glow lamp behind it)

page_text: over which a pointer ; is caused to travel at suitable intervals with that of the log
apparatus. A convenient arrangement for this purpose consists in providing the
dial b with contacts k arranged at suitable distances apart, say at every 10 divisions,
representing a corresponding number of knots, and placing them in electrical con-
nection with a conducting wire, such as 1, leading from an electric battery m, or
other source of electricity, one end of which wire is in connection with the contacts
while the other end of the wire is in connection with the pointer f. Said
contacts are so disposed that the pointer f, when influenced by its mechanism, is
caused to pass successively over them. The conducting wire from the contacts k
goes to the armature n of an induction coil o, and from this coil the return wire p
is led. The armature is provided at its free end with a tooth n¹ adapted to engage
the teeth of a ratchet wheel q mounted fast on the arbor j¹ of the pointer j. Thus,
each time the pointer f moves over or comes against a contact k, an electric current
will pass through the coil o and armature n so causing the tooth n of this latter
to be momentarily lifted out of engagement with the ratchet wheel q. This wheel,
on being released, begins to revolve under the influence of suitable mechanism,
such as a train of wheels (not shewn) in connection with a coiled spring s, and so
causes the pointer j to advance to the next division, whereupon the tooth n¹
engages the succeeding tooth and arrests the wheel until it is again operated
by the current, and so on.
In Fig. 6 the contacts k are shewn arranged at every 10 divisions on the dial b,
and the wheel q as having 10 teeth; thus the pointer j, when energised, jumps a
distance corresponding to such 10 divisions, but it is obvious that the number and
arrangement of contacts k, together with the number of teeth on the wheel q,
may be modified to suit various requirements.
A bell may be included in the circuit so as to give an audible signal each time
the pointer advances; thus a ready means is provided for ascertaining the
continued working of the apparatus.
Any other suitable electrical indicating apparatus may, however, be used.
Having now particularly described and ascertained the nature of my said in-
vention and in what manner the same is to be performed, I declare that what I
claim is:-
1. A ship-log apparatus provided with an electric incandescent lamp arranged
behind a graduated dial of translucent, or semi-transparent material, and furnished
with means for closing or opening an electric circuit, substantially as and for the
purpose set forth.
2. The combination with a ship-log apparatus, constructed as above claimed, of
indicating apparatus in electrical connection therewith, whereby the readings
of the log may be readily ascertained on a duplicate dial located in the chart-house,
or in other convenient part of the ship, and which indicating apparatus may be
combined with means for giving an audible signal at predetermined intervals,
substantially as described and illustrated in the annexed drawings.
3. My improvements in ship log-apparatus, substantially as hereinbefore des-
cribed and shewn with reference to the annexed drawings.
Dated this 19th day of February 1898.
Dated this 19th day of February 1898.
ERNEST DE PASS,
Chartered Patent Agent,
78, Fleet Street, London, and 5A, Market Street, Nottingham,
Agent for the Applicant.