AN IMPROVED SHIP'S LOG
Year: 1884

page_text: I PETER JENSEN of 33 Chancery Lane in the County of Middlesex, Fellow of
the Institute of Patent Agents do hereby declare the nature of said Invention for
"AN IMPROVED SHIP'S LOG" and in what manner the same is to be performed, to
be particularly described and ascertained in and by the following statement :-
This Invention is a hydro-aërostatic log having for its object to indicate the
speed at which a ship or vessel is running through the water, whereby it is possiblo
at any moment of the motion to read off the speed directly as indicated in knots.
The arrangement and construction of apparatus requisite for this purpose is
represented in the annexed Drawing, Figure 1 represents the whole apparatus
placed in a ship or vessel of which only part of the bottom is shown. Figures 2, 3,
and 4 represent the air gauge of the apparatus. A is an airtight vessel placed in
the interior of the ship and below the water line, from which vessel descends a
pipe B connected with the shank of a cock D fixed in a suitable place in the
bottom of the ship C. Through shell of this cock and through a hole in the
bottom of the ship a pipe E closed at both ends, is introduced, this pipe having a
little below the bottom of the ship an opening or a hole F at the one side of tho
pipe, which opening is turned in the direction, in which the ship is running. The
pipe E has at a suitable place another hole G, by which it can communicate with
the pipe B. In order to be able to withdraw and to cleanse this pipe which is
introduced watertight in the shell of the cock the cock plug H is closed immediately
the pipe has been withdrawn. From the vessel H another pipe J is carried to an
air pressure gauge K of suitable construction and placed at a suitable place
anywhere in the ship. At the motion of the ship through the water, this is pressed
up through the hole F into the pipe E and then further through the hole G into
the pipe B and up in the vessel A, which hereby serves as an air bell or air vessel.
The air bell in combination with the small bore pipes has for object partly to
render the ascension of the water into the apparatus during the passage of the ship
as little as possible, partly to balance the effect caused by the heaving of the sea.
The air in the apparatus is compressed and this pressure is indicated by the hand
of the air gauge K, which then may be so graduated, that the pressure
Paving &d1

page_text: corresponding to a given rapidity, is indicated in knots. Thus the more rapidly
the ship is running through the water, the more the pressure will be increased in
the apparatus and the greater distance the gauge hand will move to. It is ovident
that the apparatus must be adjusted for different depths of immersion or load line
and that care must be taken that it is in duo order at tho departure of the ship
which may be easily effected by means of suitable arrangement on the gauge.
A gauge suitable for the purpose is represented by Figures 2, 3 and 4. b is a metallic
disc movable round a spindle at a by means of the screw 8, c, d is a spindle pivoting
in bearings attached to the one side of the metallic disc b from this spindle c, d, an
arm fand another arm g of the shape represented by Figure 3 are projecting. On
the opposite side of the metallic disc bis a toothed segment m, n pivotting on a
pin at n this toothed segment is gearing with a little pinion, attached to the hand
spindle. The arm fis passing through an oblong hole in the metallic disc and
gears with the toothed segment at f. When the spring diaphragm r in the
hermetically closed box or casing of the gauge is acted upon by an increased air
pressure it will be bent a little outwards and act upon the lever arm g which by
means of the spindle c, d imparts the motion to the armf which again acts upon
the toothed segment which in its turn puts the little pinion on the hand spindle
in motion. On the band spindle is a fine spiral spring, which causes the motion to
-take place in the opposite direction, when the spring diaphragm in consequence of
-lessened pressure moves the opposite-way. The regulation consists now in making
the mechanism by means of the screw-s-to-get.nearer to or farther-from-the-spring-
diaphragm r.
If another kind of gauge is wanted to be used, the regulation will have to be
adapted to it. The band of the air gauge ought evidently to point to zero, when
-tho-ship-is-staying in port where no current worthy of mentioning exists.
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:-
First: The mode of arranging-for-a-ship-a-speed_measurer or hydrouërostatic
log by causing the water during the passage of the ship through it to be pressed-up-
in a conduit of pipes provided with an air bell and a pressure gauge, wheroby the
air existing before in the apparatus will be more or less compressed so as to cause
the hand to make indications on the gauge substantially as set forth.
Second-The particular arrangeinent or combination and also the construction
of the parts shown and described viz. the cock D with the pipe E the holes F and G
and the cock plug H, the air vessel A, and the pressure gauge K, all connected by
small piping substantially as and for the purposes described and shown.
Dated this Fourteenth day of August 1884.