IMPROVEMENTS IN MARINERS' COMPASSES
Year: 1879

page_text: LETTERS PATENT to William Robert Lake, of the Firm of Haseltine, Lake,
& Co., Patent Agents, Southampton Buildings, London, for the Invention
of "IMPROVEMENTS IN MARINERS' COMPASSES." A communication from
abroad by Anton Gareis, Hydrographer to the Imperial Royal Austrian
Navy, and Superintendent of the Compass Department of the Hydrographic
Office. Pola. Austria.
ealed the 19th August 1879, and dated the lat March 1879,
PROVISIONAL SPECIFICATION left by the said William Robert Lake at the
Office of the Commissioners of Patents on the 1st March 1879.
"
WILLIAM ROBERT LAKE, of the Firm of Haseltine, Lake, & Co., Patent Agents,
Southampton Buildings, London. "IMPROVEMENTS IN MARINERS' COMPASSES.'
[A
communication from abroad by Anton Gareis, Hydrographer to the Imperial
Royal Austrian Navy, and Superintendent of the Compass Department of the
Hydrographic Office, Pola, Austria.]
The present improvements in mariners' compasses have for their object a more
convenient mode of removing and reinserting or replacing the cap or socket
of the compass card, as well as the pivot-pin on which the said cap rests than'
is possible in the ordinary construction of mariners' compasses. These improve-
ments are more especially intended for fluid compasses, but are also applicable to
other kinds of mariners' compasses.
According to the present improvements the cover of the compass-box is pro-
vided with an aperture in the centre, which aperture is closed by a screw-plug or
other suitable means when the compass is in use. Through this aperture a key
can be inserted for removing and reinserting or replacing the cap of the compass-
card as well as the pivot-piu. While screwing the cap into or out of the compass-
card, the latter is raised off the pivot-pin, and kept from rotating by means of a
lifter. The said key is hollow at one end and provided with a rectangular
slot. The hollow end fits over the aforesaid cap or over the pivot, while the slot
receives a pin arranged on the outside of the cap and on the shaft of the pivot-pin.
The lifter as well as that part of the compass-card which rests on the same is
serrated to prevent the compass card from rotating while the cap is being screwed
in or out.

page_text: The upper part of the ring of the cover to the compass-box rises above the level
of the fluid, and allows the same to expand in different temperatures. The lower
part of the rings extends below the level of the compass-card and so forms an inner
compartment, and prevents the access of bubbles of air from the top of the cover to
the compass-card.
The screw-joint of the cover and the compass-box are arranged above the level
of the fluid, so that the latter cannot escape through the joint.
Any bubbles of air which may have formed may be removed by opening the
aperture in the middle of the cover. This aperture is closed by means of a screw-
cap having a valve so arranged as to allow the air to escape while the aperture is
being closed.
When the compass is not provided with a lifter for raising the compass-card, the
pivot-pin may be fixed to a screw-plug passing through the centre of the bottom of
the compass-box, and can then be removed by turning the compass-box over and
unscrewing the said screw-plug.
SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said William Robert Lake in the Great Seal Patent Office on the 29th
August 1879.
'
WILLIAM ROBERT LAKE, of the Firm of Haseltine, Lake, & Co., Patent Agents,
Southampton Buildings, London. "IMPROVEMENTS IN MARINERS' COMPASSES." A
communication from abroad by Anton Gareis, Hydrographer to the Imperial
Royal Austrian Navy, and Superintendent of the Compass Department of the
Hydrographic Office, Pola, Austria.
The present improvements in mariners' compasses have for their object a more
convenient mode of removing and reinserting or replacing the cap or socket of the
compass-card, as well as the pivot pin on which the said card rests than is
practicable in the ordinary construction of mariners' compasses.
These improvements are more especially intended for fluid or liquid compasses,
but are also applicable to other kinds of mariners' compasses.
The said improvements are illustrated in the accompanying Drawing.
Figure 1 represents a liquid-compass in vertical section, the "cardanic sus-
pension" being omitted, but A, A, indicate the level in which it lies. According
to the present improvements the upper glass cover t is provided with an aperture
in the centre in which a capsule or box a', a¹, is fitted communicating with the
compass-box, and closed by a screw-plug or valve a when the compass is in use.
If the screw plug should be lost, any other suitable stopper or an ordinary cork
may be used. The agate (or sapphire) cap c is secured into the holder à, d', and
kept in position by means of the hollow screw b, the said holder being screwed into
the conical carrier é, é, of the compass 'card, and provided at the top with a pro-
jećting stud d¹. A similar studiis arranged on the lower part of the 'pivot pin.
"

page_text: The cap may also be set directly into the screw b, and screwed with it into the
holder d, d. The lifter or arresting device is provided with two or more teeth f,f,
symmetrically distributed, and similar teeth project likewise from the lower edge
of the carrier e, e, of the compass-card.
Figure 2 shows in plan the corresponding part of the lifter with four teeth ƒ, f.
For removing the cap of the compass-card as well as the pivot-pin for the
purpose of examining or changing them, the compass card is raised from the pivot
pin by means of the lifter and the capsule a', a¹, which closes the aperture of the
cover is opened. The key h, h¹, (Figure 3) is then inserted through this aperture,
and being hollow at one end and provided with a rectangular slot h, the hollow end
fits over the top of the aforesaid holder d, d', or over the lower shaft of the pivot
pin, while the slot h receives the stud d' or the stud i.
By turning the key in the corresponding direction the serrated lower edge of the
carrier e, e, of the compass-card will first engage with the teeth ff, of the lifter,
thereby securing the compass-card, and then the holder d, d, of the cap c may be
screwed out of the carrier e, e, and can be removed through the box al, a¹. Through
the opening thus formed in the compass card, the pivot pin 8, i, can then be
screwed out and removed by means of the same key h, h'. On the opposite end h¹
the key is provided with an ordinary screw-driver for screwing off the hollow
screw b. It will be understood that both the key and the cap-setting as well as
the shaft of the pivot pin may be made of any suitable form. The re-inserting of
the pivot-pin and the cap is effected in like manner, and the capsule a¹, a¹, can
then be closed.
When the compass is not provided with a lifter for raising the compass card, the
pivot pin a may, as shewn in Figure 4, be fixed to a screw plug & passing through
the centre of the bottom t' of the compass-box, and can then be removed by
turning the compass box over, and screwing out the said screw-plug k. When the
pivot-pin 8 and its shaft l are removed, the screw-plug ke is re-inserted. Then the
compass-box is again turned to its normal position, and the compass-card is held in
position by its serrated carrier engaging with the teeth f', f', provided on the
flange m, m. The changing of the cap is effected in the manner described with
reference to Figure 1. For re-inserting the pivot-pin 8, the compass-box is
afterwards again turned over.
The screw joint of the upper part p, p, of the cover p, p, q, q, and the compass-
box B, B, is arranged above the level of the fluid, so that the latter, if rising to the
level n, n, cannot escape through the said joint. The space over the level n, n,
permits the fluid to expand under changes of temperature.
The lower cylindrical part q, q, of the cover of the compass-box on which the
lubber-line is indicated extends below the level of the compass-card, and so forms
an inner compartment that prevents the access of bubbles of air from the top of the
cover to the compass card.
Any bubbles of air which nevertheless may have formed may be removed by
opening the aperture in the capsule a', a¹, and causing the bubbles to move towards
the centre of the cover to enable them to escape there. This result will be effected
as long as the level of the fluid is higher than the under surface of the glass-cover t.
If this is no longer the case, the deficiency of the fluid will be indicated by the
cessation of the escape of the bubbles of air through the aperture in the capsule
a', a', and then so much additional fluid has to be poured into the compass box
through the said aperture, or that of the screw plug 2, as will raise the fluid-level
to about the upper surface of the glass-cover. Both during the filling up of the
compass-box and the removing of bubbles of air through the capsule a, a', the
screw plug z must be removed to permit the escape or to allow the admission of air.
The capsule a', a', is arranged with its valve a so that the said valve need not close
tightly, and it is provided with an aperture o. After the plug has been screwed
into its place, the last remnants of the enclosed air and a small portion of fluid can
escape through the aperture o in the part of the capsule a, a, above the valve,
while closing the said valve, the screw box of which is tightened by means of a

page_text: leather packing to prevent evaporation. Each time before closing the valve a the
compass box has to be inclined a little by elevating the side of the plug z to make
the fluid-level rise in the aperture of the said valve. In this position of the
compass-box the plug is to be closed first, and then after giving the compass box
its normal position the valve can be closed as above described.
As already mentioned the arrangements for removing the cap and the pivot can
be used on other mariners' compasses besides fluid-compasses.
The outer compass-box B, B, may, as shewn in Figure 1, be made of smaller
diameter beneath the screwed part of the cover to reduce the weight of the entire
compass, and also to permit contrivances for correcting or compensating the
deviations of the compass card to be arranged near the same.
Having thus fully described the said Invention as communicated to me by my
foreign correspondent, and the manner of performing the same, I wish it understood
that I claim,-
First. The compass cover t provided with a central aperture which can be opened
for removing and replacing the cap and pivot pin through the same, and for
removing any bubbles of air, substantially as described.
Second. The capsule and its valve, the holder of the cap, the carrier and lifter,
with their projecting teeth, and the shaft of the pivot pin constructed and com-
bined substantially as shewn, and the key h, h³, operating as and for the purpose
specified.
-
Third. The modification of the apparatus for changing the pivot-pin and the
cap of a compass without a lifter, substantially as described.
Fourth. The peculiar construction of the compass cover p, p, q, q, substantially
as described and as shewn in the Drawing.
Fifth. The construction of the outer compass box, substantially as described
and as shewn in the Drawing for the purpose specified.
In witness whereof, I, the said William Robert Lake, have hereunto set my
hand and seal, this Twenty seventh day of August, in the year of our Lord
One thousand eight hundred and seventy nine.
W. ROBT, LAKE. (L.S.)