An Indicator for Ships' Compasses.
Year: 1898

page_text: Date of Application, 20th Dec., 1898-Accepted, 21st Jan.,
1899
An Indicator for Ships' Compasses.
I, HARRY PEYTON ARBECAM, of 22, Exchange Place, Boston, Massachusetts,
U.S.A., Retired Sea Captain, 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:-
The object of this invention is to provide an improved indicating device for ships
compasses, whereby the bearings of an object at a distance from the ship may
be taken with accuracy and indicated at once on the dial of the compass.
My invention is an attachment to the binnacle which encloses or covers the com-
pass; and it consists in a rotatable central shaft extending vertically through a
bearing in the binnacle top and terminating inside of the binnacle a considerable
distance above the compass dial, a curved or oblique radial arm attached to
the lower end of said shaft and extending downwardly toward and nearly to the
margin of the dial, and a horizontal pointer, external to the binnacle, secured to
the upper end of the shaft in the same vertical plane as said radial arm. By
means of said pointer and shaft the bearing of any object toward which the pointer
is directed is accurately shown by the position simultaneously taken by the tip of
said arm over the margin of the 'compass dial.
The pointer is preferably tubular with external and internal sights; and it is
secured to the shaft-top rigidly or by a pivot permitting independent movement:
in vertical planes only. The radial indicating arm is light and pivoted or
counter-balanced and its tip reaches close to the margin of the dial, leaving the
view and movement of the compass unobstructed. The bearing for the vertical
shaft is preferably a flanged tube introduced through the binnacle top and held
in position by a clamping nut screwed upon said tube, and the proper height of the
shaft therein is maintained by adjustable rings or collars above and below said
tube. In the drawing Figure 1 is a perspective view of one form of binnacle
enclosing a compass and provided with my improvement.
Figure 2 is a vertical central section, showing details of the device.
A represents the binnacle frame or casing, which will be of any ordinary or
suitable form and provided with windows B for the admission of light and for
observation of the compass C which is suspended in the usual manner so that
the dial is horizontal and the magnetic needle connected thereto points always to
the north.
Centrally in the top of the binnacle I provide a circular opening to form or
receive a bearing for the vertical rotatable shaft D which connects the external
pointer E with the radial indicating arm F. As shown in Figure 2 the bearing
consists of a cylindrical tube G having at the upper end a flange or fixed collar
to rest against the binnacle top, such tube being screw-threaded to receive a
clamping nut H by which it may be held in position. Such tube may however be
otherwise secured, or the bearing may be formed integral with the binnacle top.
The shaft D is furnished with an adjustable collar J and set screw K, above and
below its bearing, to hold it at the proper height.
The external pointer E is represented as tubular and provided with terminal
.

page_text: sighting points for ordinary use, and with vertical slot and wire sights in the
ends of the tube for accurate work. The upper end of the shaft D) is represented
as slotted to receive a tongue e extending downwardly from the tubular pointer,
such shaft and tongue being connected by a horizontal pivot d.
The lower end of the shaft has a similar slot in the same vertical plane to receive
the upper part of the indicating arm F, the two being connected by a pivot f,
on which the arm is counter-balanced so that its horizontal position is not dis-
turbed by the rolling of the ship. The extremity of the arm F comes close to
the margin of the compass dial, and will indicate thereon the bearing of any object
toward which the pointer E is directed.
The curved or oblique position of the indicating arm F is of importance because
it permits the central shaft D to be shortened and not brought down to the face
of the compass. This arrangement leaves the compass dial unobstructed and affords
a plain view of the lubber mark on the dial casing, which mark denotes always
the direction of the prow of the ship.
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
1. The described indicator for ships compasses, consisting of a rotatable central
shaft extending vertically through a bearing in the binnacle top and terminating
inside of the binnacle above the compass, a pointer secured to the upper end of
said shaft and adapted to be directed or pointed toward any object on, the
horizon, and a curved or oblique radial indicating arm attached to the lower end
of said shaft and extending downwardly and outwardly nearly to the margin
of the compass dial and in the same vertical plane as said pointer, substantially
as set forth.
2. The described indicator for ships compasses, consisting of a tubular pointer
attached to the upper end of a vertical shaft which extends through the top of a
ships binnacle, in combination with a pivoted indicating arm, attached to the
lower end of said shaft above the compass, in the vertical plane of said pointer,
and extending downwardly and outwardly nearly to the margin of the compass
dial, so as to indicate thereon the bearing of any object toward which the pointer
is directed, substantially as set forth.
Dated the 20th day of December 1898.
D. YOUNG & Co..
11 & 12, Southampton Buildings, London, W.C.,
Agents for the Applicant.