IMPROVEMENTS IN MEASURING AND RECORDING ELECTRIC CURRENTS, AND IN THE APPARATUS EMPLOYED THEREIN
Year: 1880

page_text: LETTERS PATENT to Joseph Wilson Swan, of the Town and County of
Newcastle upon Tyne, Chemist, for an Invention of "IMPROVEMENTS IN
MEASURING AND RECORDING ELECTRIC CURRENTS, AND IN THE APPARATUS
EMPLOYED THEREIN.”
PROVISIONAL SPECIFICATION left by the said Joseph Wilson Swan at
the Office of the Commissioners of Patents on the 1st December 1880.
JOSEPH WILSON SWAN, of the Town and County of Newcastle upon Tyne,
Chemist. IMPROVEMENTS IN MEASURING AND RECORDING ELECTRIC CURRENTS,
AND IN THE APPARATUS EMPLOYED THEREIN."
This Invention consists of a means of measuring electric currents for electric
lamps and other purposes. In carrying out this Invention employ a clock either
independent or driven from a central power with other clocks. In connection with
the clock movement employ a plate twisted round its. axis to the extent of one
revolution: or in lieu of this a pin or pins, or an arm or arms placed round an axis,
and so arranged with reference to electro-magnet's facing the cylinder, and con-
nected with the electric light circuit, that when the current is passing through the
electric light circuit the said twisted plate, pin or pins, arm or arms rotated by the
clock movement shall actuate a counting mechanism of the nature used in meters
of various descriptions, but not otherwise, that is to say, when the lamp is not
lighted the counting action will not go on.

page_text: SPECIFICATION in pursuance of the conditions, of the Letters Patent filed
by the said Joseph Wilson Swan in the Great Seal Patent Office on the 1st
June 1881.
JOSEPH WILSON SWAN, of the Town and County of Newcastle upon Tyne.
Chemist. IMPROVEMENTS IN MEASURING AND RECORDING ELECTRIC CURRENTS,
AND IN THE APPARATUS EMPLOYED THEREIN."
My said Invention consists of a means of measuring electric currents for electric
lamps and other purposes. In carrying out my said Invention employ a plate
twisted round its axis to the extent of one revolution; or in lieu of this a pin or
pins, or an arm or arms placed round an axis rotated by clockwork or otherwise
at a uniform or known velocity, and so arranged with reference to electro magnets
connected with the electric light circuit (for example) that when the current is
passing through the electric light circuit the said twisted plate, pin or pins, arm or
arms rotated by the clock or other movements shall actuate a counting mechanism
of the nature used in meters of various descriptions, but that when the lamp is not
lighted the counting action shall be suspended.
And in order that my said Invention may be fully understood, I shall now
proceed more particularly to describe the same, and for that purpose shall refer to
the several Figures on the annexed Sheet of Drawings, the same letters of reference
indicating corresponding parts in all the Figures.
Figure 1 of the accompanying Drawings represents an end elevation of an
apparatus constructed and arranged in accordance with my said Invention for
the purpose of measuring and recording electric currents for electric lamps, and
Figure 2 is a plan of the same corresponding to Figure 1.
A is a cylinder carried in suitable bearings 1. and maintained in continuous
rotation by a clock or other means at a fixed rate, say, for example, one revolution
in fifteen minutes. Upon this cylinder are arranged a number of pins a. a. a.
(according to the number of lights to be registered), in the manner shewn in
Figure 2. Each of these pins acts upon a certain set of levers, one of which
sets will now proceed to describe, since the rest are only repetitions of the
first.
A lever B hinged at b, and kept against a fixed stop b¹ by means of a spring b",
has attached to it at c' another lever or pawl C in such a manner that its own
weight will cause its extremity to engage with the teeth of the ratchet
wheel E.
If now the pin on the cylinder A acts on the lever B the pawl will thereby
be caused to propel the ratchet wheel E to the extent of one tooth, a detent D
acted upon by a spring 2 serving to retain the ratchet wheel E in position until
the same is propelled again by the pawl C. The ratchet wheel E is connected with
a suitable counting mechanism F so as to transmit motion to the same, as will be
well understood.
An electro magnet G. the coil of which is in circuit with one of the lamps. is
placed under the arm H, which is formed of iron and mounted in an iron bracket G'
constituting one of the poles of the magnet. The arm H before the passage of a
current is drawn against the adjusting screw by the spring h, and thereby lifts,
by means of a wire or rod L. the pawl C out of the teeth of the ratchet wheel E.
so that in this position of the arm the movements of the levers B and C do not
affect any movements of the ratchet wheel E. When however the arm H is
attracted by the electro magnets G. in consequence of a current passing through
its coil, the rod L and with it the pawl C are lowered, and the wheel E will then be
· propelled one tooth for each revolution of the cylinder A. The rod L passes, loosely

page_text: through a hole in the pawl C, and has a small nut b' by which it lifts the pawl
when the arm is raised; but when the arm is attracted by the magnet it allows the
pawl C to slide up and down the rod L so as to act on the wheel E by the to and fro
motion of the lever B.
The ratchet wheel E is mounted fast on an axis 3 of the same length as the
cylinder A. and on this axis 3 are also keyed as many wheels E as there are pins
on the cylinder A. For each wheel there are the levers B and C, and also arms H
and electro magnets G. The coils of the latter are each in circuit with a different
lamp, so that the number of circuits in action will cause the same number of teeth
of wheels E to be propelled during each revolution of the cylinder A, one counting
mechanism being common to the whole.
Having now described and particularly ascertained the nature of my said
Invention, and the manner in which the same is or may be used or carried
into effect, I would observe in conclusion that what I consider to be novel and
original and therefore claim as the Invention secured to me by the hereinbefore in
part recited Letters Patent is.-
Measuring and recording electric currents by the employment of a rotating or
moving body driven at a uniform or known velocity, in combination with counting
mechanism by which motion is transmitted from such rotating or moving body
through the intervention of devices which are maintained in operation when the
electric current is not passing, but are brought into action so as to operate the
counting mechanism by or during the passage of the electric current, substantially
as hereinbefore described.
In witness whereof. I. the said Joseph Wilson Swan, have to this my
Specification set my hand and seal, this Twenty third day of May, One
thousand eight hundred and eighty one.
JOSEPH WILSON SWAN. (1..S.)