Improvements in Electric Recording Devices for Mariners' Com- passes and other Instruments having Oscillating Needles, Bars, or Dials
Year: 1892

page_text: Date of Application, 5th Apr., 1892-Accepted, 18th June, 1892
COMPLETE SPECIFICATION.
Improvements in Electric Recording Devices for Mariners' Com-
passes and other Instruments having Oscillating Needles, Bars,
or Dials.
I CHARLES Ludwig Jaeger of Maywood Avenue, Maywood, in the County
of Bergen, and State of New Jersey, in the United States of America, Student, do
hereby declare the nature of this invention and in what manner the same is to be
performed to be particularly described and ascertained in and by the following
statement:-
My invention has reference to improvements in electric recording devices and
especially to mariners recording compasses.
It consists essentially in combining with the deflecting bar or needle, a spiral
metallic recording arm which participates in the movements of the needle, said
recording arm being arranged above a narrow radial conductor, or over a metallic
plate forming a conductor. In the latter case, an insulating plate containing a
radial slot is interposed between the conductor and the recording arm, the strip
being fed across the slot in the insulating plate.
Upon this strip the deflections of the needle are registered by the passage of
sparks from the particular part of the recording arm which at the time may be
over the narrow conducting plate, or over the slot, to the conductor, the curvature
of the said recording arm being so laid out that the record left by the passage of a
spark between the point thereof which may be over the slot, or the narrow
conductor corresponds to a particular degree of deflection of the needle.
In the accompanying drawings:-
Figure 1. represents a plan or top view of a mariners compass constructed
according to my invention.
Figure 2. is a vertical section thereof in the planera, Figure 1.
Figure 3. is a sectional elevation of the compass, the section being taken on the
line y y, Figure 1.
Figure 4. is a diagram illustrating the method of producing the record.
Figure 5 is a diagram indicating the connections when a record of the ship's
speed is to be made.
Similar letters indicate corresponding parts throughout the several views.
In these drawings, the letter A designates the bowl, hung in gimbals, B is the
compass card and C the magnetic needle, all constructed and arranged as usual in
mariners compasses.
To the lower face of the needle C is secured a thin spiral strip D made from a
good conductor, aluminium being preferred, said strip participating in the movements
of the needle about the pivot a. Below this spiral strip, which I shall hereafter
term the recording arm, is secured in the bowl, a plate E of hard rubber or other
suitable insulating material, having therein a radial slot F.
Beneath this insulating plate and contiguous therewith is arranged a metallic
conductor G, (Figures 2 and 3) which may be in the form of a circular disc, or
merely a strip applied to the insulating plate below the slot in the latter.
Electrical connection is made with an induction coil R or other suitable apparatus
as follows: one wire W₁ (Figures 1. 2 and 5) is connected to the conductor G and
the other wire W' is caused to enter the bowl between the insulating plate E and
the magnetic needle C, its inner terminal being shaped to a point and arranged in.
close proximity to the needle.
The strip P upon which the ship's course is registered is passed across the slot F
either above or below the insulating plate E, suitable guide rolls as b b having
bearings in the plate being provided. The means for feeding the paper continuously

page_text: at a uniform rate may be of any usual type and form no part of my invention, the
only essential point being that the supply and take up rolls should be arranged one
above the other in the same vertical plane, to keep the compass in balance as
illustrated at Figure 3.
It is now evident that a spark will pass from that part of the recording arm
which is over the slot to the conductor G and only at this point (in view of the
insulating plate) to puncture the continually moving strip.
By referring to Figure 4 it will be seen that if the vessel is sailing due north the
outer end of the recording arm D is just across the outer terminal of the slot F,
consequently a series of perforations will be marked along the line marked zero
or N on the strip P; if the vessel now turns to N.N.E., the point of the recording
arm marked I will be brought across the slot at the point marked I to produce a
line of perforations on line I or N.N.E. of the strip &c. &c.
Assuming that the vessel is sailing due north and turns to N.N.W. part 15 of
the recording arm would be brought across the slot at point marked 15 to produce
a line of perforations along line marked 15 or N.N.W. on the strip.
In general it will be noticed that the spiral to which the recording arm is bent
extends through 360° and each degree thereof corresponds to a degree on the
compass card.
The strip P, is subdivided by transverse lines to indicate the time, so that the
course of the vessel at any time can be ascertained. The record can be duplicated
by any well known process in virtue of the perforations.
In the simplest form of the device, the insulating plate may be omitted and a
narrow radial strip of conducting material used in place of the conducting plate,
the sparks then passing from the recording arm to the conducting strip at their
intersection; or if desired the positions of the recording arm and conductor can be
reversed, i.e. the recording arm can be secured to a suitable rigid support, and a
narrow conductor secured to the needle in line with its axis.
It is evident that the means herein described can be applied equally well for
recording the deflections of a bar or needle in other devices, consequently I do not
wish to restrict myself to their use in mariners compasses.
In case it is desired to record the speed of the vessel upon the strip, suitable
connections are made with the taffrail log. In this instance the log L is provided
with a circuit closing arm I, the shaft of which is geared by wheels g. 9' to the main
shaft of the log, so as to make one revolution for each mile the vessel sails, and in
each such revolution it passes close to a contact I¹. A wire W is led from
contact I¹ to the compass and passed through the insulating plate F to within a
short distance from the strip P. A second wire W' is led from the revolving arm I
to the wire W from the induction coil R. At each revolution of the said arm I
the moving strip P is punctured by the spark, the number of punctures p indicating
the miles sailed as indicated at Figure 4.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed, I declare that what I
claim is :-
1. In a recording device, the combination of a conductor, a recording arm
arranged to revolve above said conductor and curved, as described, to bring
successive parts thereof over the conductor in its said revolution, means for feeding
a strip of paper between the two, and electrical connections, substantially as
described.
2. In a recording device, the combination of a spirally curved recording arm, an
insulating plate containing a radial slot, a conductor arranged beneath the slot,
electrical connections, and means for feeding a strip across the slot, substantially as
described.
3. In a recording compass, the combination of a recording arm participating in the
movements of the needle, an insulating plate provided with a radial slot, a conductor

page_text: arranged beneath said slot, electrical connections, and means for feeding a strip
across the slot, substantially as described.
4. A recording compass provided with means for making a record of the ship's
course and suitable connections between the log and said compass for forming a
record of the speed of the vessel, substantially as described.
Dated Aprш
C. L. JAEGER,
By Harris & Mills,
23, Southampton Buildings, London, W.C.