Improvements in and relating to Range Indicators.
Year: 1892

page_text: Date of Application, 25th Nov., 1892-Accepted, 18th Feb., 1893
COMPLETE SPECIFICATION.
[Communicated from abroad by THE AMERICAN RANGE FINDER COMPANY,
Western Electric Company's Buildings, corner Greenwich and Thames Street,
New York City, United States of America.]
Improvements in and relating to Range Indicators.
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 relates to an apparatus for transmitting to the guns or to other
points in a war vessel information concerning the distance of a target, which
distance has been previously determined by observation; as, for example, by means
of a range-finding apparatus.
In the accompanying drawings,
Fig. 1 is an electrical diagram illustrating the principle of the invention.
Fig. 2 represents the apparatus containing one transmitting and two receiving
instruments.
Fig. 3 is a sectional view, enlarged, of the cylinder in each instrument which
carries the resistance wire and of the contact arm which touches said wire.
Fig. 4 is a detail view showing the spiral groove in the cylinder in which the
wire is placed and also the contact arm.
Similar letters of reference indicate like parts.
In Fig. 1, A B is part of a conducting circuit which includes the battery C.
D is a galvanometer connected in shunt with A B; one terminal being fixed at the
point A and the other, E', being movable along the conductor A B.
When the
terminal E' is thus moved along, the resistance between the points A and E will
be varied. Hence the index of the galvanometer D may be controlled to point to
any mark or marks inscribed along its path.
Connected in multiple arc relation to the galvanometer D are two other similar
galvanometers, E and F. Obviously, if the conditions are the same in all three
galvanometers, D, E and F, the needle deflections in each will be the same.
Therefore, if D be the transmitting galvanometer and E and F the instruments
located at distant stations, an operator at D, by adjusting the travelling contact
point E', can cause in his instrument a deflection which will be reproduced at the
distant stations.
If, however, the galvanometers E and F are differently located with respect to
the galvanometer D so that in the circuit of one, as F, there is a different resistance
from that which is in the circuit of the other, as E, it is necessary to regulate said
galvanometers so that their indications will correspond to those of the transmitting
galvanometer D.
Referring now to Fig. 2, D, E and F, as before, represent three similar
galvanometers of any suitable known type, preferably that in which a coil of wire
is supported in the field of a permanent magnet; this coil assuming a new angular
position depending upon difference of potential between its terminals. The index
needles d, e, move over scales which are here preferably marked for meters or
other units of range distance.
G is a cylinder of hard rubber or other insulating material having in its ends
metal pivots, g, which do not extend entirely through the cylinder and which are
journaled in bearings, h. H is a hand-wheel by which the cylinder G can be
turned. On the cylinder G is a spiral groove, i, in which is a wire, j, of high-
resisting material. The ends of this wire connect with the pivots 9. I is a metal
rod upon which slides the sleeve J which carries the arm K extending over the

page_text: cylinder G. The arm K has a contact point E', which enters the spiral groove i
and bears against the wire ). By the rotation of the cylinder G by the hand-
wheel H the contact point E¹ is caused to move along the spiral wire j. This
construction is the same in the instruments D, E and F.
I will now describe the circuit connections. Circuit 1 proceeds by the wire 1
to binding-post 21, to pivot g through the spiral wire j on cylinder G to binding-
post 5, to wire 6, and so back to battery. This is circuit C A B in Fig. 1.
Circuit 2, in shunt with circuit 1, proceeds from binding-post 21 through the
galvanometer coil to wire 3', to binding-post 41, rod I, arm K, contact point E',
wire ; and so to binding-post 5 and wire 6 to battery C. The wire ; therefore
represents the part A B of the circuit in Fig. 1. Circuit 3 proceeds from binding-
post 21 of instrument D to wire 7, to binding-post 8 of instrument E, then through
the galvanometer coil of that instrument by wire 9 to binding-post 10, rod I,
arm K, wire to binding-post 11. and thence by wire 12 to binding-post 4 of
instrument D. Circuit + proceeds by wire 13 from binding-post 2' of instrument D
to binding-post 14 of instrument F. thence through the galvanometer coil to
wire 15, binding-post 16, rod I, arm K, wirej to binding-post 17, and thence by
wire 18 to binding-post 4 of instrument D.
While the instruments E and F are in multiple arc with instrument. D, the
galvanometer coils in E and F respectively stand in series relation with whatever
portions of their spiral wires ; as are included in the circuit. In order to adjust
the apparatus for use, the wheel H of the instrument D is turned to cause the
index-needle d to point to some desired indication. The readings of instruments E
and F (already installed at their proper distant stations) are then compared there-
with. Whatever differences appear in the indication of the needles d, e, f are
eliminated by rotating the hand-wheels H of the instruments E and F and thereby
throwing into or out of the circuit of the particular instrument under adjustment
so much of the length of the spiral conducting wire j as is necessary to cause its
associated index to give the same deflection as that of the instrument D. The
indexes of the respective instruments being thus adjusted, all indications of the
needles e and will correspond to that of the needle d. The number of instruments,
as E and F, in circuit with one transmitting instrument, as D, may be increased as
desired.
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed, as communicated to me by
my foreign correspondents, I declare that what I claim is
1. A range indicator containing a transmitting apparatus which is adjusted.to
indicate the range to be transmitted and a receiving apparatus in circuit with the
transmitting apparatus having an index which reproduces the indications of the
transmitting apparatus constructed and arranged as hereinbefore described.
2. A range indicator containing a transmitting apparatus which is adjusted to
indicate the range to be transmitted and a receiving apparatus in circuit with the
transmitting apparatus having an index which reproduces the indications of the
transmitting apparatus, and in said receiving apparatus a means of adjustment
whereby coincidence of said indications is effected, constructed and arranged as
hereinbefore described.
3. The combination in an instrument, such as D, of a galvanometer having an
index, a rotary cylinder, such as G, carrying a spiral conducting wire and a movable
contact finger bearing against said wire and caused to travel along the same by the
rotation of the cylinder; the said parts being constructed and arranged substan-
tially as hereinbefore described.
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, W.C., Agents for the Applicant..