IMPROVEMENTS IN SHIPS' LOGS
Year: 1883

page_text: LETTERS PATENT to Alexander Melville Clark of the firm of A. M and W.
Clark of 53 Chancery Lane in the County of Middlesex Fellow of the
Institute of Patent Agents for an Invention of IMPROVEMENTS IN SHIPS' LOGS
communicated to him from abroad by Louis Marie Garland of Havre in the
Republic of France, Master Mariner
>
"
PROVISIONAL SPECIFICATION left by the said Alexander Melville Clark
at the Office of the Commissioners of Patents on the 31st August 1883.
ALEXANDER MELVILLE CLARK of the firm of A. M. and W. Clark of.53 Chancery.
Lane in the County of Middlesex, Fellow of the Institute of Patent Agents,
IMPROVEMENTS IN SHIPS' LOGS." [communicated to him from abroad by Louis
Marie Garland of Havre in the Republic of France, Master Mariner]
This Invention relates to improvements in ships' logs or silometers of the kind
in which the rotation of a helical vaned rotator is transmitted by the line by which
it is towed to registering mechanism placed on the vessel, and the improvements
have reference :-
(1) To the bearings of the spindle which connects the line to the registering
mechanism and transmits the rotation thereto, the bearing being so constructed as
to support the spindle truly whilst opposing the least possible resistance to its
rotation.
(2) To the mode of suspending the register whereby the instrument may be
placed indifferently either on the port or starboard side and be consulted with
equal ease in either position.
(3) To the attachment to the line of an arrangement constituting a speed
regulator.
(4) To the mode of attaching the helical rotator to the line.
(5) To the employment of a plaited line instead of one formed of strands twisted
together as heretofore used, so as to avoid the effect produced by the torsion

page_text: imparted by the rotator to the strands in the inverse direction to that of their
twist, which torsion retards the revolution of the line and renders inaccurate the
indications of the registering mechanism.
(6.) To the location of the registering mechanism which instead of being placed
astern in the line of the keel is situated either on the port or starboard side in such
position that it may be consulted at a glance by the officer on deck. The apparatus
being situated at one side and not in the wake, enables the length of the line to be
reduced instead of being double the length of the vessel as usual to remove the
rotator beyond the influence of the broken water of the screw propeller.
In order that the Invention may be more readily understood, I have illustrated
two examples of it in the accompanying drawings.
Figure 1 is a general view of the apparatus, the indicator being supposed to be
suspended on the starboard side. Figure 2 is a detail view showing a face view of
the registering mechanism, the dial being supposed removed, and a longitudinal
section of the bearing for the spindle which transmits the rotation of the line to
the said mechanism. Figure 3 is a cross section of the spindle on line 1-2
Figure 2. Figure 4 is a detail section of part of the clock work showing how the
indicator hands are mounted. Figure 5 shows the connections of the line with
the rotator.
Referring to the latter figure, a is the hollow boss of the rotator in which the
end of the line d is received, the attachment being made by the knotted end of the
line c being tightly clamped against a shoulder b by the end f of a conical screw
plug e so that the cord must turn with the rotator
g. are the vanes of the rotator. The line d is plaited so as to offer no opposition
to the rotary motion imparted by the rotator as above explained. Referring to
figure 1 and 2 h is a casing screwing to the indicator casing. i is an eye bolt
through which the bight S of the line d is passed, the threaded stem j screwing
into the end of the spindle k. This spindle is mounted in ball bearings composed
of two circles of balls separated by a washer m whereby it is maintained truly
axial in the casing and its rotation therein is facilitated; the balls being confined
between the head n of the spindle and the bottom of the casing. The Spindle k. is
connected to the spindle q by a coupling formed by two abutments o on the disc n
which meet a cross pin p in the end of Spindle q.
The bight 8 of the line is kept open by the stretcher bar t. This portion of the
line forms a regulator or fly. It assumes by centrifugal action an elliptical form
approaching the circular as the speed of rotation of the line increases, and acts as a
fly wheel to render uniform the rotary motion transmitted from the rotator to the
Indicator. u is the indicator constructed of two plates connected by pillars v in
which is mounted the clockwork actuated by a worn on spindle q, the ratio of the
mechanism being such that the large hand moves ten times faster than the small
hand. The small hand x is fitted spring tight by a pipe on the arbor y. of the last
wheel of the traiu. w is a pinion keyed on arbor y. and actuating a wheel 1
having ten-times as many teeth and keyed on an arbor 2 together with a wheel 3
which gears with wheel 4 having a hollow arbor turning loose on y upon which
hollow arbor is fitted the pipe 6 of the large hand.
The peculiar construction of this mechanism is not however essential to the
invention. 7 is the indicator casing hung on a gudgeon 8 in the end 9 of a bow
frame 10 whose other end embraces the male portion screwing into the end of
casing h.
The casing 7 is prevented from rotating in its bearings by a set-screw 11. By
this mode of mounting the casing 7 of the Indicator on gudgeons it may be turned
half round and refixed by screw 11 according as it is changed from the port to
starboard side so that at whichever side it may be placed the division 100 will
always be at the forward side. The bow 10 is suspended by a swivel eye 12, 13,
14, so that the frame can turn freely.
The apparatus is suspended from a spar at a suitable height and in this way it
has the requisite liberty to turn in case the vessel moves asteru.

page_text: Figures 6, 7. and 8 show a modification figure 6 being a rear view of the
indicator figure 7 a section of the ball bearing for the actuating spindle and
figure 8 a birds eye view of the apparatus in uso.
I will describe with reference to these figures the improvements which
characterise this modification
To facilitate returning the indicator to zero at the commencement of an
observation a means a of resetting the hands without opening the casing is
provided.
The indicator is also provided with a third needle actuated by suitable motion-
work and indicating hundredths of knots run.
To enable the indicator to be easily brought within readable distance it is hung
by a ring b running on the spar and moved along the same by a rope d running
through a thimble eye C. e. in figure 8 are weights to sink the line sufficiently to
keep it stretched and stiff notwithstanding the motion of the waves and with the
same object. the line is sheathed with cotton.
As shown in figure 7 only one set of friction balls are used and the casing g has
two or more oil holes h covered by a sliding ring i baving a corresponding number
of holes and locked by a set screw 1. The balls f may be of stone marble
earthenware or other material not liable to rust.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said Alexander Melville Clark in the Patent Office on the 29th February
1884.
ALEXANDER MELVILLE CLARK of the firm of A. M. and W. Clark of 53 Chancery
Lane in the County of Middlesex, Fellow of the Institute of Patent Agents-
"IMPROVEMENTS IN SHIPS' LOGS" A communication to me from abroad by Louis
Marie Garland of Havre in the Republic of France, Master Mariner,
This Invention relates to improvements in ships' logs or sillometers of the kind
in which the rotation of a helical vaned rotator is transmitted by the torsion of
the towing line to registering mechanism placed on the vessel, and the improvements
have reference:
(1) To the bearings of the spindle which connects the line to the registering
mechanism and transmits the rotation thereto, the bearings being so constructed as
to support the spindle truly whilst opposing the least possible resistance to its
rotation.
(2) To the mode of suspending the register whereby the instrument may be
placed indifferently either on the port or starboard side and be consulted with
equal ease in either position.
(3) To the application to the line of an arrangement constituting a speed
regulator.
(4) To the mode of attaching the helical rotator to the line.
(5) To the employment of a plaited line instead of one formed of strands
twisted together as heretofore used, so as to avoid the effect produced by the
torsion imparted by the rotator to the strands in the inverse direction to that of
their twist, which torsion retards the revolution of the line and renders inaccurate
the indications of the registering mechanism.
(6) To the location of the registering mechanism which instead of being placed
astern in the line of the keel is situated either on the port or starboard side in such
position that it may be consulted at a glance by the officer on deck. The apparatus
being situated at one side and not in the wake, enables the length of the line to be
reduced instead of being double the length of the vessel as usual to remove the
rotator beyond the influence of the broken water of the screw propeller.
In order that the Invention may be more readily understood, have illustrated
two examples of it in the accompanying drawings.
Figure 1 is a general view of the apparatus, the indicator being supposed to be
suspended on the starboard side. Figuro 2 is a detail view showing a face view of
the registering mechanism, the dial being supposed removed, and a longitudinal
section of the bearing for the spindle which transmits the rotation of the line to
the said mechanism. Figure 3 is a cross section of the spindle on line 1-2
figure 2. Figure 4 is a detail section of part of the clock work showing how the
indicator hands are mounted. Figure 5 shows the connection of the line with the
rotator.
Referring to the latter figure, a is the hollow boss of the rotator in which the end
of the line d is received, the attachment being made by the knotted end of the
line c being tightly clamped against a shoulder 6 by the end f of a conical headed
screw-plug e so that the cord must turn the rotator. g are the vanes of the rotator.
The line d is plaited so as to offer less opposition to the rotary motion imparted
by the rotator than if it were twisted as above explained. Referring to
figures 1 and 2, h is a casing screwing to the indicator casing. i is an eye bolt
through which the bights of the line d is passed, the threaded stem j screwing
into a hole tapped in the end of the spindle k. This spindle is mounted in ball

page_text: bearings composed of two nests of balls separated by a washer m whereby it is
maintained truly axial in the casing and its rotation therein is facilitated, the balls
being confined between the head of the spindle and the bottom of the casing.
The spindle is connected to the spindle q by a clutch coupling formed by two
abutments o on the disc n which meet across pin p in the end of spindle q.
The bight 8 of the line is kept open at its forward portion by the stretcher bar t.
This portion of the line forms a regulator or fly. It assumes by centrifugal action
an elliptical form approaching the circular as the speed of rotation of the line
increases, and acts as a fly wheel to render uniform the rotary motion transmitted
from the rotator to the indicator. u is the indicator constructed of two plates
connected by pillars in which is mounted the clock work actuated by a worm r
on spindle g the ratio of the mechanism being such that the large hand moves ten
times faster than the small hand. The small hand x is fitted spring tight by a pipe
on the arbor y of the last wheel z of the train. w is a pinion keyed on arbor y
and actuating a wheel 1 having ten times as many teeth and keyed on an arbor 2
together with a wheel 3 which gears with wheel 4 having a hollow arbor turning
loose on y upon which hollow arbor is fitted the pipe 6 of the large hand.
hand being actuated by the gear just described will make ten revolutions for each
revolution of the small hand.
This
The peculiar construction of this mechanism is not however essential to the
invention, as any other giving an equivalent result might be substituted. 7 is the
indicator casing hung on a gudgeon 8 in the end 9 of a bow frame. 10 whose other
end embraces the male portion screwing into the end of casing h. The casing 7 is
prevented from rotating in its bearings by a set-screw 11. By this mode of
mounting the casing 7 of the indicator ou gudgeons it may be turned half round
and refixed by screw 11 according as it is changed from the port to starboard side
so that at whichever side it may be placed the division 100 will always be at the
forward side. The bow 10 is suspended by a swivel eye 12, 13, 14, so that the
frame can turn freely on this swivel as an axis to accomodate itself to the pull of
the towing line.
The apparatus is suspended from a spar at a suitable height (say about 8 feet
above the deck) and in this way it has the requisite liberty to turn in case the
vessel moves astern.
Figures 6, 7 and 8 show a modification, figure 6 being a rear view of the
indicator, figure 7 a section of the ball bearing for the actuating spindle and
figure 8 a birds eye view of the apparatus in use.
I will describe with reference to these figures the improvements which
characterise this modification.
To facilitate returning the indicator to zero at the commencement of an
observation a means a of resetting the hands without opening the casing is
provided. The indicator is also provided with a third hand actuated by suitable
motion work and indicating hundreds of knots run.
To enable the indicator to be easily brought within readable distance without
unshipping the spar it is hung by a ring b running on the spar and moved along
the same by a line d running through a thimble eye c. e in figure 8 are weights to
sink the line sufficiently to keep it stretched and stiff notwithstanding the motion
of the waves and with the same object the line is sheathed with cotton.
As shown in figure 7 only one set of friction balls are used and the casing g has
has two or more oil holes h covered by a sliding ring i having holes which may be
made to correspond when required with those of the casing or turned out of
correspondance therewith the ring being locked by a set screw.
The balls may
be of stone marble earthenware or other material not liable to rust.
Having described the nature of the said Invention and the manner of performing
the same I declare that what I claim as the Invention to be protected by the
hereinbefore in part recited Letters Patent is:
1 In a ship's log wherein the rotation of the rotator is communicated by the
torsion of the line to the registering mechanism the construction combination and

page_text: arrangement of the double and single ball bearings substantially as herein described
and represented in figures 2 and 7.
2nd In a ship's log of the kind herein specified the combination with the casing
containing the double or single set of ball bearings of the ring cover for the oil
holes substantially as described and represented in figures 6 and 7.
3rd In a ship's log of the kind herein specified the combination of the casing the
double or single set of ball bearings the disc headed spindle turning therein and the
clutch coupling connecting said spindle to the registering mechanism substantially
as described and shown in figures 2 and 7.
4th The mode of attaching the line to the rotator substantially as specified and
shown in figure 5
5th The employment of a plaited in lieu of a twisted line, for the purpose
specified.
6th The bight of the line held open by a stretcher to act as a fly as described.
7th The mode of suspending case containing the registering mechanism sub-
stantially as described and represented at 7, 8, 9, 10, 11 and h in figure 2 whereby
the instrument may be suspended either on the port or starboard side as specified.
8th The means described and referred to by the letters b c d in figures 6, 7, and 8
in combination with the registering mechanism for bringing the latter within
readable distance as described.
9th The line provided with weights e and sheathed in cotton substantially as and
for the purpose specified.
In witness whereof I the said Alexander Melville Clark, have hereunto set my
hand and seal this Twenty ninth day of February A.D. 1884.