Improvements in Apparatus for Measuring Distances or Ascertaining the Course of a Vessel.
Year: 1892

page_text: Date of Application, 6th Sept., 1892-Accepted, 21st Jan., 1893
געגן בסט
Improvements in Apparatus for Measuring Distances or Ascertaining
the Course of a Vessel.
We, THE LOWRY MANUFACTURING COMPANY, of New Jersey, United States
of America, and AMBROSE CONSTANTINE DUNN, of New Jersey, aforesaid,
Inventor 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 :-
This invention relates to telemeters.
which
The purpose is, mechanically, to ascertain the distance of a stationary object from
two points of observation; also the course of a vessel. The principle upon
the invention is based is, that if, in a triangle, two angles and their included side
are known, the other two sides are determined.
With these objects in view the invention consists essentially of a graduated base-
plate upon which is secured a guide rod having two graduated discs mounted
thereon, one of which is stationary and the other capable of a longitudinally sliding
movement, two graduated arms each pivoted at one end to the centre of one of the
discs and adapted to radiate at any angle therefrom and with relation to each other;
furthermore the invention consists of a graduated base-plate, a guide-rod supported
centrally above and parallel to the base-plate, having a stationary disc secured at
one end thereof and a movable disc adapted to slide thereon to and from the
stationary disc, and be secured at any point upon the guide-rod, both of the discs
being graduated around their edges to indicate degrees and having revolvable
compass-cards thereon, two graduated arms each pivoted respectively to the movable
and stationary discs and designed to radiate at any angle therefrom; and, finally the
invention consists of a base-plate graduated upon two opposite edges thereof, a
guide-rod supported centrally above and parallel to the base-plate and having a
stationary and a movable disc mounted thereon, the discs being capable of vertical
and horizontal adjustment a compass-card thereon capable of circular adjustment,
two graduated arms pivotally secured respectively to the stationary and the movable
discs, and adapted to radiate at any angle therefrom and with relation to each
other.
In the accompanying drawings forming part of this Specification, and in which
like letters of reference indicate corresponding parts:
Figure 1 is a perspective view of the telemeter.
Figure 2 is a longitudinal sectional view taken from one side of the movable disc
a portion of the device being shown in side elevation.
Figure 3 is a detached plan view of one of the discs showing the compass-card
countersunk therein and the rim provided with degree marks, and
Figure 4 is a central transverse sectional view through the movable disc showing
the movable disc overlapping the stationary disc, the stationary disc being in side
elevation.
In the drawings: A represents a base-board upon which is supported a base-
plate A graduated similarly upon two opposite edges thereof, the numbers of the
graduations being inverted with relation to each other, to facilitate their being read
from either side of the instrument. B is a guide rod supported in brackets a above
the base-plate and parallel thereto C C are two discs, having each a circular
recess c to hold compass-cards c² c³ free to revolve in the recesses, the discs, at the
edges being conveniently divided into quadrants from zero to ninety degrees the zero
marks being in alignment with the guide-rod B.
The disc C is stationary upon a round guide-rod B with relation to the disc Cª

page_text: or may be permanently located at one end thereof, while the disc C is movable.
The means for supporting the disc C and, if desired, also the disc C consist
of a collar c encircling the guide-rod B and of a downward projection * from
the disc integral with the collar. The disc may be secured at any point on the
rod by a set-screw e passing through the collar, and bearing against the rod.
Carried centrally on each side of the collar are vertically adjustable pointers c
the outer ends of which register with the graduations on each side of the plate A2.
These pointers have vertical slots c in their upper ends through one of which
passes a horizontal screw c and on this screw is a jam-nut c³ to bear against
the base of the pointer, the other pointer being held by a set screw clo.
DD are two arms having a series of graduations thereon corresponding to the
graduated scales on the. base-plate A². These arms are respectively pivotally
secured at one end in the centre of the disc C and the disc C2 and are adapted to be
radiated at any angle from the discs and then to be secured rigidly by thumb-
screws dd. The zero points of the graduated scales on the arms D D² correspond
with the pivotal points thereof.
The vertical adjustment of the discs C C2 and the circular adjustment of the
compass-cards are common to each while the movable disc C, only, is,
generally, only capable of horizontal adjustment. The vertical adjustment of the
discs is to enable the arms D D to be brought into direct line with any object
which may be above or below the level of the instrument and thus insure greater
accuracy.
In operation, the base-board is secured firmly in position as upon the rail of
a vessel with the guide-rod in the line of direction of movement of the vessel
or other moving object between the two points of observation; the compass-card
of the stationary disc is then turned so that the points thereof will register with
the state of the ship's compass at the time of taking the initial observation;
the outer end of the pivoted arm of the stationary disc is then brought into line
with a stationary object such as a light-house, the disc being rocked up or down,
as the object is high or low and is then fixed in position, marking an angle on
the disc. After the vessel has pursued a straight course for some time the
number of miles is determined, and the movable disc is then adjusted on the rod
at a point opposite the number on the base-plate corresponding with the number
in miles travelled, the compass-card is set and the pivoted arm of the movable
disc is adjusted and fixed as the arm of the stationary disc was adjusted and
fixed in the initial observation. The arm of the stationary disc is thus crossed
by the arm of the movable disc and the numbers on the arms at the crossing
indicate, respectively, the distance between the vessel and the object at the
initial and final points of observation, while by comparison of the state of the
compass at the initial point of observation with its state at the final point of
observation the course of the vessel between the two points is determined, and may
be marked on the chart.
With this instrument, recognition of a vessel's exact position may be determined
by a person of ordinary intelligence. The instrument may be used with equal
accuracy on land.
Having now particularly described and ascertained the nature of this said
invention and in what manner the same is to be performed, we declare that
what we claim is:-
1. In a telemeter the graduated base-plate graduated discs mounted on the base-
plate one of which is stationary and the other movable horizontally and both of
which are capable of vertical movement and the pivoted graduated arms, substan-
tially as described.
2. In a telemeter the graduated base-plate graduated discs mounted thereon each
of which has a countersunk compass-card therein one of which discs is stationary
and the other movable and the pivoted graduated arms substantially as described.
3. In a telemeter the graduated base-plate graduated discs mounted thereon each

page_text: of which has a countersunk compass-card therein, one of which discs is stationary
and the other horizontally movable and both of which are capable of vertical
movement and the pivotted graduated arms, substantially as described.
4. In a telemeter the graduated base-plate graduated discs mounted thereon one
of which is stationary and the other horizontally adjustable and both of which are
capable of vertical adjustment compass-cards secured on the discs and adapted to
revolve thereon graduated arms pivoted at one end centrally one upon each disc
and binding screws for securing the arms at any degree of angle, substantially as
described.
5. In a telemeter the graduated base-plate the round guide-rod secured thereon
the stationary disc having the pivoted arm and the movable disc having the collar
enclosing the rod a set-screw for retaining the collar in place and a pivoted arm
attached to the disc substantially as described.
Dated this 29th day of August 1892.
W. P. THOMPSON & BOULT,
Agents for the Applicants.