Improvements in Apparatus for Finding the Range and Position of Distant Objects.
Year: 1892

page_text: Date of Application, 1st Mar., 1892-4ccepted, 28th May, 1892
COMPLEIE SPECIFICATION.
[Communicated from abroad by BRADLEY ALLAN FISKE, of the "Beresford,"
New York City, United States of America, Lieutenant, United States Navy.]
Improvements in Apparatus for Finding the Range and Position of
Distant Objects.
I, HENRY HARRIS LAKE, of the firm of Haseltine, Lake & Co., Patent Agents,
45 Southampton Buildings in the County of Middlesex, 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 invention is an apparatus for finding the position of a distant object. It
depends upon the principle of first determining a fractional portion of a conducting
body bearing in length a ratio to the azimuth angle of the object, and then measuring
the electrical resistance of that length.
The communicator has already obtained English Patents Nos. 5351, 13566, and
18185, of 1890, for range finders which measures the distance of an object from the
observer, which range finder 1 briefly re-describe hereafter in this Specification.
By my present invention, I am enabled to add to that range finder the new
capacity of a position finder.
Referring to the accompanying drawings, Fig. 1 represents in diagram one form
of my range finder here introduced for purposes of illustration.
A B is the base line upon which are pivoted telescopes L L', which move over
ares, h, of conducting material. T is the position of the distant object. The
telescopes L L are connected to a battery, i. The corresponding ends of the
arcs are connected in Wheatstone bridge circuit by the wires a, b, c, d, with
the galvanometer g.
Assume the telescope L to be first in the position A. E parallel to the position BD
of the telescope L. Let the galvanometer y then show zero because of the balance
in both parts of the bridge. Let the telescope L be moved to the position CA to
direct it upon the object T. It will then have moved over an angle CA E. The
galvanometer y will then measure the resistance of the arc E C thrown into
the circuit; and, as I have already fully explained in prior Patents, in this way
the distance of the object T can be deduced.
Referring now to Fig. 2, it will be apparent that in the upper part of said figure,
the arrangement of the wires a, b, c, d, the battery i, the indicator y and the
ares and telescopes L L', is the same as already described in connection with
Fig. 1; but in Fig. 2, I now show an arc, 2 similar and parallel to arc h, and an
arc, 3, similar and parallel to arc '. The telescopes L and L' are each supposed
to be provided with two contacts insulated one from the other, which respectively
move over the arcs or 13. Connected with the telescopes L L are
wires a b c d arranged in Wheatstone bridge connection with the extremities of
the ares h³, with the battery, and with the indicator g'. There are, therefore,
two distinct systems in the instrument; one for range finding communicating with
the ares, and one for position finding communicating with the arcs h³ ³.
There is, however, an important difference in the mode of connecting the bridge
wires to the arcs in the two cases. The wire a is connected to one end of the
are ', and the wire b, which is a continuation of the wire a, to the corresponding
end of the arc ; and the same is true of the wires c d. The wire a' is connected
to one end of the arc 2; but its prolongation, the wire &, is not connected to the
corresponding end of the arc 3, but to the opposite end of said arc; and this
arrangement is equally true of the wires c¹ d'.
The effect of this change of connections will best be understood from Fig. 1. If
the arc
were rotated on the axis O X, it will be plain that the same result in

page_text: changing connections would be produced, as is already described; and that if, before
said rotation, the position of the telescope L were on the line A E, its position after
said rotation would be on the line A E', and therefore, the galvanometer y would
show zero with the telescopes in the position A. E' and B D.
If the telescope L be then directed on the object T, it will pass over the
are CE, which is plainly equal to the azimuth angles T B Y and T A. X. But
let F on the line A B be the point from which the observation is to be reckoned.
Therefore, the azimuth angle at that point will be T F Z, which is practically
equal to one half the sum of the angles T BY and T A X, or one-half of the
angle measured by the arc C E¹.
The effect of changing the connections in the manner illustrated in Fig. 2, is, as
has been stated, the same as rotating the arc h, which operation is, therefore, not
necessary. It simply remains to graduate the indicating instrument so that it will
show a deflection proportional to half the arc C E', when the azimuth angle of the
point can be obtained from said instrument by direct reading. Instead of
graduating the galvanometer gl for direct reading, I may employ the arrangement
shown in Fig. 2, and use a zero method. The construction adapting the instrument.
to this apparatus is as follows
Between fixed points, m n and m³ n', upon a suitable base, extend lengths o and o¹
of the bridge wires, and the resistance of each length equals the resistance of one
are 2 or 3 Moving along these wires are sliders insulated from one another,
but connecting respectively to the galvanometer y'. The carriages, which supports
these sliders, has a nut which receives the screw t, which is journaled in the base
and rotated by the milled head u. Upon the base is applied a scale, which may be
graduated to show angular bearing, beginning from zero at the middle of the scale,
and increasing towards either side. As the arrangement of such an apparatus as
this has been fully explained in prior Patents, it is not necessary to repeat it here
further than to state that the sliders are normally adjusted to show zero on the
seale, and that when the telescopes are moved so as to produce a given angle one to
the other, thereby throwing resistance in the manner already described in the
circuit and so deflecting the galvanometer g¹, the sliders may be moved in one
direction or the other to change the relations of the bridge arms a¹¹c' d' until the
galvanometer g' is brought back to zero. The extent of movement of the
sliders is then shown on their scale, from which the angle of bearing may be at
once read.
2"
In Fig. 2, I have shown the arcs h³ and h³ as separate, each telescope
carrying two contact springs. In place of this construction, may use a single arc,
having both sets of bridge wires connected to it; in which case, it will be necessary
to use but one battery, as i.
Having now fully ascertained and described the nature of the said invention and
in what manner the same is to be performed, I declare that what I claim is :-
1. An apparatus for finding the position of distant objects, constructed and
arranged substantially as hereinbefore described.
2. An apparatus for finding both the range and position of a distant object,
constructed and arranged substantially as herein before described.
Dated this 1st day of March 1892.
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, W.C., Agents for the Applicant,