IMPROVEMENTS IN SHIPS LOGS AND IN APPARATUS FOR AUTOMATICALLY RECORDING THE COURSE AND DISTANCE
Year: 1883

page_text: LETTERS PATENT to James Campbell J.P. of Arkley House Barnet in the
County of Middlesex for an Invention of "IMPROVEMENTS IN SHIPS LOGS
AND IN APPARATUS FOR AUTOMATICALLY RECORDING THE COURSE AND
DISTANCE
"
PROVISIONAL SPECIFICATION left by the said James Campbell at the Office
of the Commissioners of Patents on the 29th December 1883.
JAMES CAMPBELL J.P. of Arkley House Barnet in the County of Middlesex
" IMPROVEMENTS IN SHIPS LOGS AND IN APPARATUS FOR AUTOMATICALLY RECORDING
THE COURSE AND DISTANCE
"
This invention has for its object improvements in ships logs and in apparatus for
automatically recording the course and distance.
My improved log is towed behind the ship and it contains a rotator giving
motion to a train of gear which slowly rotates a pair of rollers. Between these
rollers a cord passes which consequently partakes of the movement of the rollers.
The cord connects the log with the ship and the movement of the part of the cord
which is on ship-board indicates the progress of the vessel. On board the ship the
cord may pass over rollers connected with a train of counting wheels actuating
pointers to show upon a dial the run of the ship.
Or the cord in its slow movement may actuate a wheel with points upon it a
sheet of paper being arranged in contact with the wheel.
The paper which is perforated by the points is supported upon a table controlled
by a compass needle. Cardinal points may be marked upon the table.
The length of the line of punctures produced on the paper under these conditions
will indicate the distance run by the ship and the direction of the line upon the
paper will indicate the course of the ship.
This recording mechanism is capable of being used with electrical and other logs.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said James Campbell in the Patent Office on the 28th June 1884.
JAMES CAMPBELL J.P. of Arkley House Barnet in the County of Middlesex
" IMPROVEMENTS IN SHIPS LOGS AND IN APPARATUS FOR AUTOMATICALLY RECORDING
THE COURSE AND DISTANCE"
This invention has for its object improvements in ships logs and in apparatus for
automatically recording the course and distance.
My improved log is towed behind the ship and it contains a rotator giving
motion to a train of gear which slowly rotates a pair of rollers. Between these
rollers a cord passes which consequently partakes of the movement of the rollers.
The cord connects the log with the ship and the movement of the part of the
cord which is on ship board indicates the progress of the vessel. On board the ship
the cord may pass over rollers connected with a train of counting wheels actuating
pointers to show upon a dial the run of the ship.
Or the cord in its slow movement may actuate a wheel with points upon it a
sheet of paper being arranged in contact with the wheel. The paper which is
perforated by the points is supported upon a table controlled by a compass needle.
Cardinal points may be marked upon the table and on the disc or paper. The
length of the line of punctures produced on the paper under these conditions will
indicate the distance run by the ship and the direction of the line upon the paper
will indicate the course of the ship.
This recording mechanism is capable of being used with electrical and other logs.
In order that my invention may be fully understood I will proceed to describe
more in detail the manner in which I prefer to construct the apparatus. The
improved log much resembles externally the so called "Patent Log." It consists
of a metal case conical at the fore end with a cylindrical body tapering to the rear
where it terminates in a section upon which screw or inclined blades are fixed.
The body and fore part of the log are prevented from revolving in the water
by flat fins with which the body is provided but the terminal section is free to
revolve and it does revolve when the log is drawn through the water in consequence
of the action of the water against the inclined blades. The axis of the revolving
part passes by a packed gland into the interior of the body and it carries a crank
arm. The body receives within it a frame in which the following gearing is mounted.
At the rear end of the frame in the centre is a longitudinal axis having at one end
a worin and at the other an arm or finger which when the frame is in place is in
the path of the crank pin driven by the revolving part of the log consequently the
worm and its axis revolve. The worm gears with a wheel of twenty teeth upon a
transverse axis upon which there is a second similar worm driving a similar wheel
also on a transverse axis. On this axis is a roller about three quarters of an inch
in diameter revolving in contact with another similar roller. The rollers are on
parallel axes and are geared together to revolve at like surface speeds. The rollers
are grooved to receive between them a cord which they nip and the grooves are
roughened by indented lines so that the cord may not slip between the rollers but
be wound forward by them as they rotate. The cord is endless and of a length
convenient for towing the log behind the ship. The cord passes out of the case of
the log through two stuffing boxes one on either side of the pointed fore end of the
log. The stuffing boxes allow the cord to run freely. The movement of the cord
may conveniently be six or eight inches for each knot of the ship's run.
On board the ship the arrangements are as follows: the endless cord is placed
over a grooved wheel or roller upon a transverse horizontal axis. The size of this

page_text: wheel or roller may conveniently be such that the movement of the endless cord
will cause it to rotate once for each knot of the run.
The axis is carried in bearings in a frame and it has in connection with it a set
of counting wheels like a gas meter index by which the rotations of the axis or in
other words the number of knots run by the ship are counted. Beneath the axis
there is on gimbals a circular table similar to a compass card and similarly controlled
by a magnetic needle. The table is mounted to turn freely on a central pivot and a
short tube attached to the underside of the table surrounds the stem of the pivot.
The lower end of the tube fits this stem nearly and the table is thus kept steady
upon the pivot. Upon the table a sheet of paper is laid and it is kept in place by
a light ring or weight resting on rollers upon it but it is nevertheless free to be
moved in any direction upon the surface of the table.
The horizontal axis which takes its motion from the endless cord has upon it a
dise in which a pin is inserted and once in each revolution as the pin comes to the
top it lifts a cradle which as it rises lifts the table with it off the pivot. Upon a
cross bar immediately over the pivot there is a wheel with points like the rowel of
a spur which when the table is thus lifted perforates the paper which is raised
against it. At the same time also a projection on the disc in passing the point
wheel or rowel moves it forward the distance between one point and the next and
in this movement the rowel carries the paper with it. The rowel is provided with a
light retaining spring which prevents it moving except when forced forward by
the projection on the disc. The rowel or point wheel also may be supplied with
ink to cause it to produce clearer marks upon the paper. At each operation soon
after the mark is produced the table descends with the paper upon it and it settles
down again with the magnet needle attached to it in a North and South position.
At the end of the mile run or other prearranged distance the table is again lifted
off its pivot and held, the paper is again imarked and is again moved a short
distance in the fore and aft direction. Thus the paper receives and preserves on its
face a record of the distance and direction of the ship's run.
Having thus described the nature of my said invention and in what manner the
same is to be performed I declare that what I claim is :-
First. A log imparting motion to an endless cord and so transmitting to the
ship an indication of the distance run substantially as described.
Second. An apparatus for automatically recording the course and distance run
by a ship consisting of a table controlled by a compass needle and carrying the
paper or surface on which the record is to be made and of instruments which at
uniform intervals in the run as measured by the log automatically hold the
table then mark the record surface and move it a step forward substantially as
described.
Third.—The combination of apparatus for measuring and automatically recording
a ship's course and distance substantially as described.
In witness whereof I the said James Campbell have hereunto set my hand and
seal this Twenty sixth day of June in the year of our Lord One thousand eight
hundred and eighty four.
ז זפתrג
JAMES CAMPBELL (L.C.)