Improved Electric Top for Gyroscopes and the like.
Year: 1899

page_text: Date of Application, 11th Dec., 1899-Accepted, 10th reum revo
Communicated from abroad by BERLINER MASCHINENBAU ACTIEN-GESELLSCHAFT,
• vormals L. SCHWARTZKOPFF, of 17-18, Chauséestrasse, Berlin, N., Germany,
Manufacturers.]
Improved Electric Top for Gyroscopes and the like.
I, WILLIAM PHILLIPS THOMPSON, F.C.S., M.I.M.E., of the Agency for Foreign
Patent Solicitors, 322, High Holborn, in the County of Middlesex, 6, Lord Street,
Liverpool, and 6, Bank Street, Manchester, both in the County of Lancaster, and
Lower Temple Street, Birmingham, in the County of Warwick, Civil Engineer,
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 present invention relates to an electric top for the gyroscope which in spite
of its light weight can receive a large amount of motive power, and is perfectly
symmetrically constructed.
"
:
Figure. 1 of the accompanying drawing illustrates the new top in combination
with an instrument for geographical determination of position, which latter;
however, is not claimed as new in the present application.
Figure 2 shews the top itself, partly in elevation and partly in section...
The instrument consists of two systems each of three Cardan' rings, placed one
inside another. The outer system, comprising the rings a b c is in stable equi-
librium and forms a plane constantly parallel to the apparent horizon. The
inner system of rings, which comprises the rings ef g, is, on the contrary in uni-
form balance, and thus gives the required mobility in relation to the outer
0 system, to the top h which is always persistently parallel to its axis and is 'sup-
ported in the innermost ring g.
In order to be able to measure the angle formed by the axis of the top with
regard to the apparent horizon, a ring i is arranged in the space between the
ring a mounted on the pillars d and the ring b, said ring i, in consequence of the
25 clutches ; holding the ring b, being able to revolve round its axis which is
vertical to the plane of the ring b. An accurately radially adjusted telescope 1
is movably secured on the ring i with which the ends of the top axles are observed
On the graduated circle i is read off the inclination of the top axle to the appar
ent horizon, that is, to the plane of the ring b. The latter itself is provided wit
30 degrees and compass card. This enables the direction of the compass needle an
thus the position of the top, the axis of which stands parallel to the axis of th
earth, to be controlled by means of the projection of the axis of the top an
the plane of the ring i.
"
The rings c, e, f, g, are, as usual, not entirely made out of electrically conduc
danial but consist of two metal 'halves insulated from each other.

page_text: this manner the current conducted through wires to the ring c, by means of the
pins y, can find its way through the ring itself as far as the two axle ends of
the top without having to use wires, collector brushes or other devices impeding
free motion.
The top (see Figure 2) forming the object of the present invention which is
driven with single phase alternating current, is constructed as follows:
The shaft of the top placed in the ring g consists of two equal parts and m
which are nevertheless not conductingly connected with each other. Each half
of the shaft is screw threaded at two places the first of which holds the bush n
for a ball bearing, while on the inner one is placed the metal boss o which sup-
ports the inducing portion of the motor. The iron core 9 of the inducing part
formed of plates in the usual manner, and held together by insulated screws is
encircled by the insulating lining r of the boss o. The ends of the winding are
Joined to the boss o.
On the boss s of the ball bearing are fastened the caps t which bear the outside
and induced portion of the motor. This part also consists of a core u of iron
plates which is held between the caps having insulated linings w, by means of
insulating screws. In this case the winding consists of short-circuited copper
rods x.
The arrangement is so planned that the friction of the induced parts upon the
bushes n is less than that of the pivots of the shafts and m in the ring b so that
it commences to run without a jerk, whilst at the first increase of torque, both
parts can rotate in opposite directions until finally as the acceleration decreases
to the constant speed, the inner inducing part remains stationary. The rotating
part is outside and consequently it can receive the greatest possible energy, as the
latter in equal size and number of revolutions increases with the square of the
distance from the rotary axis.
Two of the instruments described above are necessary for geographical survey.
For this purpose, the top axles of the two instruments are first placed in a spot
the geographical position of which is accurately known, in the requisite position,
that is to say, so that they are vertical to each other and that one thereof is
parallel to the earth axis. The axle of this top will then form at different
degrees of latitude and that of the other top at different degrees of
longitude a different angle with the meridian. Then the motors are
set working, which during the whole time that the instruments are in use are
driven by alternating current of constant potential and frequency. Slight varia-
tions in the number of revolutions do not noticeably affect the accuracy. If it is
desired to determine the position of a given place, it is only necessary to read off
the angle of inclination of the top axles of the two instruments to the apparent
horizon and the result is obtained after a perfectly simple calculation or by means
of tables.
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. An improved electric top comprising a motor, the inducing part of which is
secured on the top axle which does not share the movement of rotation, while
the induced part can revolve on the said axle substantially as described.
2. An improved electric top in which the top axis stationary with regard to
the rotation, is likewise revolubly placed in the adjustment of the top for prevent-
ing jotting or jarring, but with slightly greater friction than that between the
axle of the top and the rotary body, so that when the motor is going it goes for
a little contrary to the normal direction of revolution and then stops of itself,
substantially as described with reference to the accompanying drawing.
3. The improvement in the construction of an electric top in which the non-
rotating top axle is also rotatably supported so that it can turn with slightly

page_text: increased friction as compared with the rotating body for the purpose of avoiding
any jerk on starting the apparatus, substantially as described.
4. In combination with a gyroscope the improved electric top constructed and
operating substantially as described and shewn in the accompanying drawings.
e December 1899.
Dated O
4
W. P. THOMPSON & Co.,
London W.C., Patent Agents for the Applicant.
Datcu
W. P. THOMPSON & Co.,
322. High Holborn, London. W.C., Patent Agents for the Applicant.
AM