Improvements in and relating to Mariners' Compasses.
Year: 1894

page_text: PROVISIONAL SPECIFICATION.
Improvements in and relating to Mariners' Compasses.
I, JAMES MORTON, Nautical Instrument Maker, of Villiers Street South,
Sunderland, and Mill Dam, South Shields, in the County of Durham, do hereby
declare the nature of this invention to be as follows
My invention relates to mariners' compasses and particularly to the suspension
of the compass bowl and of the card therein, with the objects of isolating the card
so as to reduce as far as possible its vibrations due to movements of the vessel in
order that its indications may not be unduly disturbed thereby, and of facilitating
adjustment of the card when required.
For suspending the compass bowl from the gymbal ring which is slung in any
suitable manner within the casing I fix to the bowl at two opposite points (at right
angles to the gymbal suspensions) a ring, made of suitable material and either
continuous or in two semicircular hoops. The ring is made flexible in vertical
direction at its points of connection with the bowl, when continuous by suitably
reducing the material thereabouts, and when in semicircular hoops by pivotting or
jointing their extremities to the bowl. At the points of suspension of this ring
from the gymbal ring I employ the usual knife edge bearings, and further connect
the ring to the bowl at or about such points at either side by one or more springs
of suitable kind. These are preferably helical metallic springs, for fixing the ends
of which I have designed a special arrangement. This consists in recessing the
terminal hooks into countersunk holes in both ring and bowl so that after the
holding screw has been inserted the hooks cannot open out, and a firm, flush, and
neat attachment is effected. Instead of metallic springs I may however use rubber
springs, or a combination of metal and rubber or other suitable resilient substance
or substances.
My improvement in suspending the card refers to cards suspended by thread,
wires, or other filaments. For such I provide an arrangement for facilitating the
central adjustment of the card or the taking up of slack of such filaments when
stretched. The filaments are supported centrally from a ring carried upon a
jewelled cap working on a central pin-point in the known manner; but instead of
fixing or passing the filaments through holes in said ring as is the usual practice I
twist together the inner ends of pairs of adjacent filaments leaving end loops, and
1 form on the ring a series of peripheral hooks over each of which is passed the
loop of one of the twisted filaments so that when adjustment is required the loop
of any, filament may be easily unhooked, and then by twisting it one way or the
other its length can be adjusted to a nicety before re-booking. In similar manner
I also make provision for facilitating the central adjustment of the filaments
carrying the magnetic needles. For this purpose I make the radial connections
double and twist them together, aud on the compass card I form a groove, or a
suitable, number of separate pockets or grooves through holes in which I pass the
outer end of each twisted radial filament which is knotted. This is done in such
manner that when required to rectify any deformation of the figure, by drawing
outwards any knot and twisting or untwisting the filament, the length of that

page_text: connection to the figure can be accurately adjusted. I may also adopt this last-
described method for the central ring instead of the hooks above described.
Dated this 26th day of September 1894.
Improvements in and relating to Mariners' Compasses.
1, JAMES MORTON, Nautical Instrument Maker, of Villiers Street South,
Sunderland, in the County of Durham, 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 relates to mariners' compasses and particularly to the suspension of
the compass bowl and of the card therein, with the objects of isolating the card so
as to reduce as far as possible its vibrations due to movements of the vessel in
order that its indications may not be unduly disturbed thereby, and of facilitating
adjustment of the card when required.
For suspending the compass bowl from the gimbal ring, which is slung in any
suitable manner within the casing, I fix to the bowl at two opposite points (at
right angles to the bowl suspensions) a ring made of suitable material and either
continuous or in two semi-circular hoops as illustrated. The ring is made flexible
in vertical direction at its point of connection with the bowl, when continuous by
suitably reducing the material thereabouts, and when in semi-circular hoops by
pivotting or jointing their extremities to the bowl. At the points of suspension
of this ring from the gimbal ring employ the usual knife-edge bearings, and
further connect the ring to the bowl at or about such points at either side by
one or more springs of suitable kind. These are preferably helical metallic
springs, for fixing the ends of which I have designed a special arrangement.
This consists in recessing the terminal hooks into countersunk holes in both ring
and bowl so that after the holding screw has been inserted the hooks cannot open
out, and a firm, flush, and neat attachment is effected. Instead of metallic springs
I may however use rubber springs, or a combination of metal and rubber or other
suitable resilient substance or substances.
In order that this part of my invention may be fully understood I have
illustrated same in the accompanying drawings.
Fig. 1 is a plan of compass and casing, the covering glass and cap being
removed on the right hand side; Fig. 2 is a central section of same;
Fig. 3 is a perspective view illustrating my improved method of suspending the
bowl with two half hoops pivotted thereto;
Fig. 4 is a detail of alternative arrangement hereinafter explained.
Similar letters refer to similar parts.
C represents the casing from which the gimbal ring, D is slung by the
diametrically opposite slings d. d. A is the bowl, B the bowl ring, and b. b. its
knife edged supports bearing upon the gimbal ring D. If the ring B is made in
two sections, the ends of each hoop are pivotted or jointed to the bowl at each side
as at B¹ in Figs. 1 and 3; or equivalently to obtain the required resiliency I may
fix to each end of a two-part ring a strip of metal such as 1, Fig. 4, the centre of
which is fixed to a stud attached to the bowl A at diametrically opposite points.
If the ring is continuous I reduce the material about the said points of fixing to
the bowl as shown by dotted lines in Fig. t, and by thus affording a certain
degree of resiliency the friction at the joints is minimised. S S represent a pair of
helical metallic connecting springs, their upper end hooks being recessed in the

page_text: ring B, and their lower end hooks into the bowl blocks a a. behind the holding
screws a¹ a' for the purpose above referred to.
My improvement in suspending the card refers to cards suspended by threads,
wires, or other filaments. For such I provide an arrangement for facilitating the
central adjustment of the card or the taking up of slack of such filaments when
stretched. This is illustrated in Figs. 1, 2, 5, 6, and 7 af the drawings, Fig. 5
being a part plan of a compass card P, and Figs. 6 and 7 enlarged details. The
filaments are supported centrally from a ring R carried upon a jewelled cap J
working on a pin point j supported on a central column in the known manner;
but instead of fixing or passing a continuous filament through holes in said ring as
is the usual practice I twist together, as at F, the inner ends of pairs of adjacent
filaments FF, Fig. 5, leaving end loops f, and I form on the ring a series of
peripheral hooks x, x, x, over each of which is passed the loop f of one of the
twisted filaments F, so that when adjustment is required the loop of any filament
may be easily unhooked, and then by twisting it one way or the other its length
can be adjusted to a nicety before re-booking. In similar manner I also make
provision for facilitating the central adjustment of the filaments G carrying the
magnetic needles N. For this purpose I make the radial connections G₁ double,
and twist them together, and on the compass card P1 form an annular groove p,
see specially Fig. 6, or equivalently a suitable number of separate pockets or
grooves may be employed, through small holes g in which I pass the outer end of
each twisted radial filament G which is knotted at its outer end g¹. This is done
in such manner that when required to rectify any deformation of the figure, by
drawing outwards any knot g¹ and twisting or untwisting the filament G', the length
of that connection to the central figure formed by the filaments G can be accurately
adjusted. I may also adopt this last described method for attaching the filaments F
to the central ring R instead of using the hook and loop arrangement above
described. For this purpose I make the ring R of a form such as is shown in the
section, Fig. 7, and I forin knots f¹ upon the inner ends of each of the twisted
radial filaments F, and as will be readily understood, by twisting or untwisting
same their length can be accurately adjusted.
Having now particularly described and ascertained the nature of this inven-
tion and in what manner the same is to be performed, I declare that what I
claim is :-
1. In a mariner's compass, suspending the compass bowl from the gimbal ring in
such manner
as to afford there to resiliency and freedom of vertical motions,
substantially as and for the purposes above set forth.
2. The arrangement for suspending the compass bowl from the gimbal ring, in
which the bowl is provided with a ring such as D with knife-edged bearings, and
either made in two sections each pivotted or jointed at its ends to opposite points
of the bowl, or in one hoop reduced in vertical thickness and fixed at opposite
points to the bowl (said points of fixing to bowl being diametrically at right
angles to the knife-edged suspensions,) in combination with spring connections
from ring to bowl at the knife-edged suspensions so that the bowl ring is rendered
flexible in vertical directions, substantially as and for the purpose hereinabove set
forth.
3. The special arrangement for fixing the ends of the opposite bowl ring
springs S S respectively to the bowl ring and to the bowl, substantially as described
and illustrated.
4. In a mariner's compass, the use of twisted filaments for suspending the
compass card and for holding the needle carrier whereby adjustment is effected
by twisting or untwisting such filaments, substantially as above described.
5. For suspending the card the arrangement of pairs of filaments F F twisted
together at the parts F, and either with (1) terminal loops fadapted to pass over
books on central bearing ring R, or (2) passed through holes in ring R and
kuotted at the ends, as and for the purpose set forth.

page_text: 6. The arrangement for adjusting the filaments carrying the needles N consisting
of double twisted radial filaments G! passed through holes in an annular groove,
or equivalent in the annular compass card P and knotted, and adapted for use
substantially as and for the purpose described.
Dated this 25th day of June 1895.
For the Applicant,
J. C. CHAPMAN,
70, Chancery Lane, London, W.C., Chartered Patent Agent.