Distances Travelled by Ships or Navigable Vessels, Applicable also for Indicating the Speed of Flowing Fluid.
Year: 1885

page_text: Distances Travelled by Ships or Navigable Vessels, Applicable
also for Indicating the Speed of Flowing Fluid.
I, JOHN SMITH RAWORTH, of N° 24 Brazenose Street, in the City of Manchester,
Electrical Engineer, do hereby declare the nature of said invention for "IMPROVE-
MENTS IN INSTRUMENTS OR APPARATUS FOR INDICATING DISTANCES TRAVELLED BY
SHIPS OR NAVIGABLE VESSELS APPLICABLE ALSO FOR INDICATING THE SPEED OF
FLOWING FLUID to be as follows:-
My invention has reference to ship's logs of the kind in which indicating or
recording mechanism is worked electrically by means of a small screw towed by
the ship or vessel whose speed it is desired to ascertain and my invention is
designed to enable batteries and moving contacts which are open to objection in
practice to be dispensed with in such apparatus.
For this purpose the screw which rotates in the water contains or is attached to
or forms part of a small magneto-electric machine-the wire coils of which are
enclosed in a watertight case communicating with the ship by one or two conductors
laid inside the line that tows the log. The magnet is caused by the screw to
rotate outside the case containing the coils and causes alternate currents to traverse
the conductors, which being led to or through any suitable indicating or recording
instrument will operate the same and produce the required indications on the dial
or diala
According to one arrangement the conductors are led to a polarized electro-
magnet in the indicating apparatus and cause the armature, which is pivotted, to
oscillate and in so doing to actuate a ratchet wheel or escapement wheel which
through suitable gearing gives the required indications.
In some cases I provide a supplementary indicating instrument to shew at sight
the speed of the vessel. This instrument comprises a clockwork mechanism
provided with a device such as a cam, which determines the length of time during
which a special indicator shall be periodically driven by the instrument that is
worked from the log. The point to which this indicator is moved during each
period indicates the rate at which the vessel is travelling for the time being. At

page_text: the end of each period the mechanism of the supplementary indicator returns to
the zero or starting point, leaving the indicator of the instrument in the position
to which it has just been moved-At the next stroke should the vessel be
travelling faster the indicator will be moved to a corresponding extent; or should
the vessel be travelling slower, the indicator will be returned to a corresponding
position under the action of a spring.
As will be evident apparatus according to my invention may be constructed
in various forms and may be employed to indicate the speed at which fluid is
flowing.

page_text: Distance by ships of US, appävänie
also for Indicating the Speed of Flowing Fluid.
I, JOHN SMITH RAWORTH, of No 24 Brazenose Street, in the City of Manchester,
Electrical Engineer, do hereby declare the nature of said Invention for "IMPROVE-
MENTS IN INSTRUMENTS OR APPARATUS FOR INDICATING DISTANCES TRAVELLED BY
SHIPS OR NAVIGABLE VESSELS APPLICABLE ALSO FOR INDICATING THE SPEED OF
FLOWING FLUID to be as follows:-
"
My invention has reference to ship's logs of the kind in which indicating or
recording mechanism is worked electrically by means of a small screw towed by
the ship or vessel whose speed it is desired to ascertain and my invention is
designed to enable batteries and moving contacts which are open to objection in
practice to be dispensed with in such apparatus.
For this purpose the screw which rotates in the water contains or is attached to
or forms part of a small magneto-electric machine the wire coils of which are
enclosed in a watertight case communicating with the ship by one or two conductors
laid inside the line that tows the log. The magnet is caused by the screw to
rotate outside the case containing the coils and causes alternate currents to traverse
the conductors, which being led to or through any suitable indicating or recording
instrument will operate the same and produce the required indications on the dial
or dials.
It is obvious that when the screw does not form part of the magneto machine,
but is attached thereto, the connecting link or line may be of any convenient or
desired length so that the screw rotator being in the water, the magneto machinė
may be either in the water, or in the air, even if desired on the taffrail to which
it may be secured by a suitable swivelling fork.
According to one arrangement the conductors are led to a polarized electro-
magnet in the indicating apparatus and cause the armature, which is pivotted, to
oscillate and in so doing to actuate a ratchet wheel or escapement wheel which
through suitable gearing gives the required indications.
In some cases I provide a supplementary indicating instrument to show at sight
the speed of the vessel. This instrument comprises a clockwork mechanism
provided with a device such as a cam, which determines the length of time during
which a special indicator shall be periodically driven by the instrument that is
worked from the log. The point to which this indicator is moved during each
period indicates the rate at which the vessel is travelling for the time being. At
the end of each period the mechanism of the supplementary indicator returns to
the zero or starting point, leaving the indicator of the instrument in the position
to which it has just been moved-At the next stroke should the vessel be travelling
faster the indicator will be moved to a corresponding extent; or should the vessel
be travelling slower, the indicator will be returned to a corresponding position
under the action of a spring.

page_text: THE DRAWINGS.
Figures 1 to 9 represent the arrangement of the instrument in which the screw
blades are rigidly attached to the magnets, and the coil is drawn through the water
by a tow line containing a conductor or conductors. Figures 10 to 13 represent
an indicator for showing the number of revolutions made by the magnet.
Figures 14 to 16 represent an indicator for showing the speed at which the
vessel is travelling for the time being. Figures 17 and 18 represent the coil
and magnet as arranged for attachment on board the vessel, the screw only being
drawn through the water. Figures 19 and 20 represent the instrument applied
to indicate the speed at which fluid is flowing.
Referring to the arrangement in which the screw forms part of the case of the
magneto machine, Fig. 1 is the side elevation, Fig. 2 the end elevation, Fig. 3
a longitudinal section, Fig. 4, 5, and 6 are transverse sections at A, B, and C
respectively, Fig. 7 represents the parts of the instrument which are attached to
the tow line and do not revolve, Fig. 8 is the end elevation of magnet, and Fig. 9
the side elevation. a is a coil of fine insulated wire which is wrapped on a soft
iron core of H section a,. On the front end of the core is screwed a gun-metal
cap A, which forms the fixed bearing for the balls C, C, and is screwed to receive
the non-turning parts of the log dы, d₁, d₁. On the back end of the core is screwed
a tail piece, a, which takes a bearing in the wood bush by. The coil and core are
enclosed in a thin brass tube α, which is afterwards soldered to the cap q, and the
tail piece a One end of the coil a₁ is in metallic contact with the brass cap dg,
the other end is in contact with the metallic bush a-This bush is insulated from
the cap a, by the non-conducting bush ag. After the coil is thus connected the
cylinder containing it is run up full of paraffin wax. The magnet is formed of
two arms b₁, b₁ fixed on a yoke b, it is held in position in the case c, of the
instrument by the screwed plug b The set screw b, is to adjust the amount of
play of the balls C. C. The piece c, is screwed on the front end of the case c, and
forms the moving bearing for the balls. c is an air chamber on which the screw
vanes c, C, C, are fixed-it is screwed on the plug b. after the magnet is fixed in
position. d is a concentric cable forining a tow line-it consists of an inner core
containing one or more conducting wires outside which are laid several small wires
which are used as the return connection between the indicator and the instru-
ment these are again covered by insulating material and hemp or metallic
sheathing. The inner wire is connected to the 'metallic contact peg d, which
is fixed in the non-conducting bush ds. The peg d₂ makes contact with the
bush a when the nose piece d, is screwed home in the piece d¸. The outer
wires of the cable are connected to the metallic nose piece d. A complete
circuit is thus established between the coil and the indicator, the current passing
from one end of the coil through the insulated peg and central conductor to the
indicator and returning through the outer wires and the casing of the instrument
to the other end of the coil. In the case of iron ships the return conductor may
be dispensed with, the water forming a connection between the casing of the
instrument and the ship. c. c. are bronze balls to diminish the friction caused
by the pull of the vanes and casing on the cap ag.
When the instrument is towed
through the water, the vanes cause the casing to revolve, carrying with it the
magnet. The coil and other parts shown in Fig. 7 being prevented from turning
by the tow line, alternate currents are generated in the circuit, one current being
impelled in each direction for each complete revolution of the magnet. The water
is allowed to flow through the instrument between the casing and the cylinder
containing the coil for the purpose of lubricating the balls and the bearing b. The
magnet may be plated with copper to prevent corrosion.

page_text: Referring to the indicator for shewing the number of revolutions made by
the magnet, Fig. 10 is the front elevation; Fig. 11 shews the polarized electro-
magnet and escapement; Fig. 12 is an end elevation, with case in section;
Fig. 13 is a front elevation with case in section and front plate removed. e, is
an electro-magnet the bobbins of which are wound with fine wire; Ę is a soft
iron keep pivoted between the poles of the magnet so that it can oscillate in the
vertical plane; e, is a permanent magnet which polarizes the keep e; e, е are
pallets rigidly attached as shewn to the oscillating keep; fi is an escapement
wheel having 20 teeth which is actuated by the pallets е e. One current in each
direction passed through the coils of the electro-magnet give one complete oscil-
lation of the keep to and fro-this moves the escapement wheel one tooth forward.
The escapement wheel f₁ is geared to the shaft carrying the one knot dial plate f
by a train of the ratio of 100 to 1. The shaft which carries the one knot dial fo is
geared to the shaft carrying the hundred knot dial f, by a train of the ratio of
100 to 1. The hundred knot dial f, is geared to the thousand knot dial f, by a
train similar to that used to drive the hour hand of a clock but of the ratio of
10 to 1. The hundred knot dial is not attached rigidly to its shaft but is driven
from it by means of a friction spring. The hundred and thousand knot dials may
therefore be moved round for adjustment without actuating the rest of the train
and escapement. The numbers on the dials are read off opposite a fixed pointer.
The whole of the mechanism of the indicator may be lifted bodily out of the case.
The two ends of the coils on the electro-magnet are attached respectively to two
insulated contact pieces 91 91 when the mechanism is put in position in its case,
these contact pieces make contact with two springs g. 9. These springs 9, 9, are
connected to a suitable concentric coupler g, for the attachment of a concentric
conductor. An indicator geared as above described is suitable for use with an
instrument the magnet of which makes two thousand revolutions per knot.
Referring to the indicator for shewing the speed at which the vessel is travelling
for the time being, Fig. 14 is a front elevation; Fig. 15 an end elevation with
case in section; Fig. 16 a plan with case in section. This indicator shews the speed
at which the vessel is travelling in knots per hour when used in conjunction with
an instrument the magnet of which makes 2,000 revolutions per knot. h₁ is a
space left in the case for a clock of ordinary construction. The tooth wheel h, is
driven round by the clock at the rate of one revolution per minute. The tooth
wheel h, is driven round by the wheel h, at the rate of two revolutions per minute.
On the same shaft as the wheel h, is a cam h, which actuates a lever. h. The
lever he is furnished at its upper end with a paul h. The paul wheel m₁ is
mounted on an independent shaft which also carries the cam wheel m. The
curved lever m is held in contact with the cam wheel me by the spring m At
the completion of each revolution of the cam h, the lever h, is brought back into
the position shewn in the figure by the spring h, bringing the paul wheel m₁ with
it one tooth forward. The effect of this is that the lever m, is raised and depressed
by the action of the spring m, and the cam wheel me for alternate half minutes.
0, 0, are pallets moved by a polarized electro-magnet as above described. They
actuate the escapement wheel o₂. The shaft on which the escapement wheel o̟, is
mounted is geared to the shaft og. On the shaft og is mounted a pinion of. The
shaft is lifted and depressed by the action of the lever m.. When the shaft is
depressed the pinion o gears with a spur wheel mounted on the shaft o. To one
end of the shaft o, is attached a carrier og
The other end of the shaft is made
fast to the centre of a spiral spring o, which brings it back to the zero point when
the pinion o, is lifted out of gear. p, is a small shaft carrying at one end the
pointer p, and at the other end the arm po which is actuated by the carrier o.
Ps is a small spiral spring which tends to bring the pointer p. back to zero.
the shaft p, there is a cone p, which is pressed into a conical bearing by the
spring p, the, friction thus established is sufficient to prevent the spiral spring p.
from carrying back the pointer to zero. The cycle of the instrument is as follows:-
Supposing the pointer to be standing at zero and the pinion o̟ to be at the
03
On

page_text: commencement of the half minute in which it is out of gear, for half a minute the
oscillation of the keep produces no effect beyond turning the escapement wheel
and shaft o. The lever m, now throws the pinion o, into gear and the shaft os
moves round against the action of the spring o, taking with it the shaft p, by
means of the carrier o. At the expiration of the minute the pinion o̟ is again
thrown out of gear, the carrier flies back to zero under the action of the spring o
but the pointer is maintained at the furthest point it has attained by the friction
of the cone ps. This completes the cycle. Shortly before the completion of each
minute the projection h, on the minute wheel h, presses the end of the lever p, and
by lifting the spring P, releases the cone p, allowing the pointer to fly back under
the action of the spring p, until checked by the carrier o The position of the
pointer is thus corrected at the expiration of every minute. The ratio of the gear
in this indicator is such that four hundred oscillations of the pallets give one
revolution of the pointer.
Referring to the arrangement in which the screw rotator does not form part of
the magneto machine but is attached thereto by a link or line,-Fig. 17 is an
elevation, Fig. 18 a plan of the instrument as adapted for such arrangement.
8, is a bracket for attachment to the taffrail of a vessel. 8, is a fork swivelling
in it. The coil and other non-rotating parts of the instrument are attached to the
cap 8, which is supported on trunnion pins in the fork 82. The case 8. contains the
magnet. 8, is an eye for the attachment of the tow line by means of which the case
and magnet are caused to rotate.
Referring to the arrangement of the instrument for the measurement of flowing
fluids, Fig. 19 is the end elevation and Fig. 20 the side elevation of part of a pipe
the flow of the fluid in which is to be measured. v, is the revolving part of the
instrument supported by the bearing v v, is the non-revolving part of the
instrument attached to the bracket v. v, is a metallic pipe conveying the con-
ducting wire or wires to the outside of the moveable cover v6 to which the
instrument is attached.
Having now particularly described and ascertained the nature of my said
invention, and in what manner the same is to be performed, I declare that what
I claim is
(1). For the purposes above set forth, the use of a magneto-electric machine or
generator, capable of producing alternate or intermittent currents by the rotation
of a magnet around or in proximity to a non-revolving coil or armature.
(2). The use of a circuit embracing the generator coil, the conducting wires or
bodies, and the coils of the indicator permanently closed, without moving contacts.
(3). For the purpose above set forth the use of an indicator arranged to give a
constant indication of speed by repeated adjustment of a finger or dial as shown in
Figures 14, 15, and 16.'
Dated this thirtieth day of March 1996.