IMPROVED MEANS AND APPARATUS FOR DISTRIBUTING AND REGULATING ELECTRIC CHIDDENTS TO WORK LAMPS AND OTHER ELECTRIC APPARATUS."
Year: 1878

page_text: LETTERS PATENT to Charles William Siemens, of No. 12, Queen Anne's Gate,
Westminster, in the County of Middlesex, for the Invention of "IMPROVED
MEANS AND APPARATUS FOR DISTRIBUTING AND REGULATING ELECTRIC
CHIDDENTS TO WORK LAMPS AND OTHER ELECTRIC APPARATUS."
PROVISIONAL SPECIFICATION left by the said Charles William Siemons at
the Office of the Commissioners of Patents on the 7th June 1878.
CHARLES WILLIAM SIEMENS, of No. 12, Queen Anne's Gate, Westminster, in the
"IMPROVED MEANS AND APPARATUS FOR DISTRIBUTING
County of Middlesex.
AND REGULATING ELECTRIC CURRENTS TO WORK LAMPS AND OTHER ELECTRIC
APPARATUS."
It is sometimes necessary or advantageous to divide an electric current into a
number of separate currents, so as to supply a number of lamps or other electric
instruments or machines from one source of electricity; but such division is
attended with difficulties in respect of the proper distribution of the several
currents, and their regulation proportionately to the work which they have to
perform.
My Invention relates to means and apparatus whereby such distribution of
electric currents is effected with automatic regulation, and to the application of like
means of automatic regulation to electric lamps, whether they are worked by
separate electric currents or by portions of a divided current.
For the purpose of distributing a current of electricity into a number of branches
I make part of each branch in the form of a thin strip of metal, such as copper,
so that it can be readily heated by the passage of electricity through it, and can
rapidly part with its heat by radiation. Its temperature varying with the strength

page_text: of current passing through it, its length undergoes alterations by expansion and
contraction, and I employ these changes of length to give movements to portions
of a commutating apparatus, whereby circuits of more or less resistance can be
introduced into the main circuit. Thus when, owing to the passage of an excess of
electricity through a strip such as I have described, it becomes elongated, its
elongation brings into the circuit a subsidiary circuit of greater resistance, which
has the effect of diminishing the amount of electricity passing through the strip.
It is advantageous to divide the resistance circuits thus acted on into a number of
separate circuits, each being brought after the other into the main circuit, so that
the alteration of resistance is effected gradually or by steps.
The resistance circuits may either be in the form of long conductors, freely radi-
ating heat, or in the form of liquids.
The strips employed for the purpose above mentioned are subjected to the tension
of adjustable weights, and the tension on them can be regulated as required by
adjusting screws while the apparatus is at work.
Instead of making the expansion and contraction of the metallic strip give
movement, as above described, to parts of commutators for the purpose of intro-
ducing resistance circuits, the strip may be arranged to apply as train to a portion
of the circuit consisting of carbon or analogous material, capable of having its
electrical resistance varied according to the strain put upon it.
I apply apparatus, acting in a similar manner, to effect the automatic adjustment
of the carbons of electric lamps, so as to regulate their distance by the action of the
electric current passing through them. For this purpose I mount the carbons (or
such other materials as may be employed for producing the luminous arc) in vertical
slides in the usual way, the slide of the one which is the more rapidly consumed
being the heavier, and having on it a rack gearing with the larger of two pinions
on one axis, while a rack on the slide of the other gears with the smaller of these
pinions. By this arrangement the one carbon, namely, that which is most rapidly
consumed, tends by the superior weight of its slide to descend, causing the other to
ascend through a smaller distance, so that the focal position of the luminous are
remains nearly constant.
I connect the common axis of the pinions by means of gearing to a rotating flyer
or to a paddle revolving in liquid for the purpose of retarding the movement of the
slides, and to some convénient moving part of the gearing I apply a friction break
connected to the conducting strip by which the electric current is conveyed to or
from the carbons, this strip being adjusted so that when it becomes expanded by
heat beyond a certain degree it causes the break to be applied.
This arrangement operates in the following manner: The carbons are adjusted,
in the first place, so that when an electric current is transmitted the luminous arc
is formed. As the material wastes the carbon slides, actuated by the superior
weight of the heavier, approach each other, putting in motion the gearing. If they
tend to approach too closely, the resistance to the passage of the electric current
being diminished, a larger quantity of electricity passes through the conducting
strip, which thereby becoming heated expands and causes the break to be applied,
so as to retard or arrest the movement of the carbons. The carbons being still
consumed the electric resistance increases as the distance between the carbon points
becomes greater, and the conductor then passing less current becomes cooled and
relieves the break, permitting a more rapid approach of the carbons. Thus the
approach of the carbons is automatically adjusted so as to maintain their distance
nearly uniform and a nearly constant passage of electric current through them.
In order to provide for the first lighting of the lamp, or for lighting it in
case of accidental extinction, I connect the lower carbon to the armature of an
electro-magnet on its slide. The coil of this magnet is brought into an circuit
whenever the conducting strip becomes shortened beyond a certain point in con-
sequence of reduction of its temperature. When this happens the arinature above
mentioned is attracted, and the lower carbon is thus raised in its slide to meet the

page_text: upper carbon, thus completing circuit and kindling the lamp. The conducting
strip thereupon becoming heated expands so far as to break the contact for the
electro-magnet and the lower carbon then drops to its normal position.
SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Charles William Siemens in the Great Seal Patent Office on the 7th
December 1878.
CHARLES WILLIAM SIEMENS, of No. 12, Queen Anne's Gate, Westminster, in the
County of Middlesex. "IMPROVED MEANS AND APPARATUS FOR DISTRIBUTING
AND REGULATING ELECTRIC CURRENTS TO WORK LAMPS AND OTHER ELECTRIC
APPARATUS."
It is sometimes necessary or advantageous to divide an electric current into a
number of separate currents, so as to supply a number of lamps or other electric
instruments or machines from one source of electricity; but such division is
attended with difficulties in respect of the proper distribution of the several
currents, and their regulation proportionally to the work which they have to
perform.
My Invention relates to means and apparatus whereby such distribution of
electric currents is effected with automatic regulation, and to the application of like
means of automatic regulation to electric lamps, whether they are worked by
separate electric currents or by portions of a divided electric current.
For the purpose of distributing a current of electricity into a number of branches
I make part of each branch in the form of an exceedingly thin strip of metal, such
as copper, silver, or iron, so that it can be readily heated by the passage of
electricity through it, and can rapidly part with its heat by radiation. The tem-
perature varying with the square of the strength of current passing through it, its
length undergoes alterations by expansion and contraction, and I employ these
changes of length to give movements to portions of a commutating apparatus,
whereby circuits of more or less resistance can be introduced into the main circuit.
Thus when, owing to the passage of an excess of electricity through a strip such
as I have described, it becomes elongated, its elongation brings into the circuit a
subsidiary circuit of greater resistance, which has the effect of diminishing the
amount of electricity passing through the strip. It is advantageous to divide the
resistance circuits thus acted on into a number of separate circuits, each being
brought after the other into the main circuit, so that the alteration of resistance is
effected gradually or by steps.
The resistance circuits may either be in the form of long conductors, freely radi-
ating heat, or in the form of liquids.
The strips employed for the purpose above mentioned are subjected to the tension
of adjustable weights or springs, and the tension on them can be regulated as
required by adjusting screws while the apparatus is at work.

page_text: Instead of making the expansion and contraction of the metallic strip give
movement, as above described, to parts of commutators for the purpose of intro-
ducing resistance circuits, the strip may be arranged to apply a strain to a portion
of the circuit, consisting of carbon or analogous material capable of having its
electrical resistance varied according to the strain put upon it.
I apply apparatus, acting in a similar manner, to effect the automatic adjustment
of the carbon points of electric lamps or their equivalents, so as to regulate their
distance by the action of the electric current passing through them. For this
purpose I mount the carbons (or such other materials as may be employed for
producing the luminous arc) in vertical slides in the usual way, the slide of the one
which is the more rapidly consumed being the heavier, and having on it a rack
gearing with the larger of two pinions on one axis, while a rack in the slide of the
other gears with the smaller of these pinions. By this arrangement the one carbon,
namely, that which is most rapidly consumed, tends by the superior weight of its
slide to descend, causing the other to ascend through a smaller distance, so that
the focal position of the luminous are remains nearly constant.
I connect the common axis of the pinions by means of gearing to a rotating flyer
or to a paddle revolving in a liquid for the purpose of retarding the movement of
the slides, and to some convenient part of the gearing I apply a friction or other
break connected to the conducting strip by which the electric current is conveyed
to or from the carbon, this strip being adjusted so that when it becomes expanded
by heat beyond a certain degree it causes the break to be applied.
This arrangement operates in the following manner:-The carbons are adjusted
in the first place so that when an electric current is transmitted the luininous arc
is formed. As the material wastes, the carbon slides actuated by the superior
weight of the heavier approach each other, putting in motion the gearing. If they
tend to approach too closely, the resistance to the passage of the electric current
being diminished, a larger quantity of electricity passes through the conducting
strip, which thereby becoming heated expands, and causes the brake to be applied.
so as to retard or arrest the movement of the carbons. The carbons being still
consumed, the electric resistance increases as the distance between the carbon points
becomes greater, and the conductor then passing less current becomes cooled and
relieves the brake, permitting a more rapid approach of the carbons. Thus the
approach of the carbons is automatically adjusted, so as to maintain their distance
nearly uniform and a nearly constant passage of electric current through them.
In order to provide for the first lighting of the lamp, or for lighting it in case of
accidental extinction, I connect the lower carbon to the armature of an electro-
magnet on its slide. The coil of this magnet is brought into a circuit whenever
the conducting strip becomes shortened beyond a certain point in consequence of
reduction of its temperature. When this happens the armature above mentioned
is attracted, and the lower carbon is thus raised in its slide to meet the upper
carbon, thus completing the circuit and kindling the lamp. The conducting strip
thereupon becoming heated expands so far as to break the contact for the electro-
magnet, and the lower carbon then drops to its normal position.
DESCRIPTION OF THE DRAWINGS.
Fig. 1 of the accompanying Drawings shews a side view, Fig. 2 a plan, and Fig. 3
an end view of one arrangement of my before-described apparatus for automatically
regulating the electric current by causing the expansion or contraction of an
exceedingly thin strip of metal to introduce a greater or less amount of resistance
into the circuit.
A is an exceedingly thin strip or ribbon of metal, such as silvered copper or iron,
which should not be thicker than from one to two thousandth part of an inch, in
order that it may give off its heat rapidly. This strip is secured at its one end to

page_text: turning which the tension of the strip can be regulated, and which is connected to
the circuit wire F. The spindle D has fixed upon it a lever G with weighted tail G¹,
so arranged that the weight acts in opposition to the strain on the metal strip, so
that any elongation of the strip caused the weight to pull the lever G over in the
direction towards the strip, while the contraction of the strip causes the lever to
move in the contrary direction. A number of metal bars H, H, by preference of
platinum, or platinised or gilt copper, are supported, insulated from each other on a
frame I of ebonite or other insulating material, and have their alternate ends con-
nected to each other by means of resistance coils J of low conductivity, as shewn,
so that all of them together constitute a zig-zag conductor with a number of
resistance coils introduced at intervals. The first bar is electrically connected to
the strip A by a wire K, and the last bar is electrically connected to the circuit
wire F by a wire K'. From each bar there is suspended by a conducting strip
contact pieces L, L, which when not touching each other, as shewn at Fig. 1, prevent
the passage of an electric current from the one to the other, so that a current
passing in at the first bar H has to traverse the whole of the zig-zag line and
resistance coils before arriving at F. If on the other hand the first contact piece L
be pressed against the second one then the current will pass from the first bar H
through these two contact pieces and their suspending strips to the second bar
without passing through the resistance coil, and thus the resistance to the current
will be reduced. In like manner if the second contact piece be pressed against the
third one the second resistance coil will be cut out of the circuit, and so on, until by
pressing all the contact pieces together the whole of the resistance coils are cut out
of the circuit, the current passing wholly or in great part direct from the lever G
through all the contact pieces L to the contact spring P, which is in electrical con-
nection with the wire Fi
From this arrangement it will be seen that if the tension of the metal strip A be
so adjusted by the screw E that when the desired quantity of electric current is
passing through the strip will hold the lever Gin such a position as by means of its
upper end to press a certain number of the contact pieces L together, and thus to
cut a corresponding number of the resistance coils out of the circuit, then on a
greater quantity of electric current than is required passing through the strip A
the heating and consequent expansion of this will permit the weighted arm G¹ to
draw the lever G away from the contact pieces to such an extent as to bring a
certain number of them out of contact. By thus bringing a certain number of the
resistance coils into the circuit the resistance will be increased, and consequently
the electric current diminished again, whereupon the strip A. in cooling and con-
tracting will move the lever back into its original position, in which it presses the
required number of contact pieces together. If on the other hand the strength of
the current decreases below the normal amount the metal strip A in cooling and
contracting will move the lever so as to press a greater number of the contact
pieces together, thereby decreasing the resistance of the circuit and increasing the
strength of the current.
By making the metal strip A exceedingly thin, as before described, so that it
parts very rapidly with its heat, and by so arranging its connection to the spindle D
that the motion resulting from its expansion and contraction is considerably
multiplied by the lever G, it will be seen that the slightest changes in the strength
of the current will affect the apparatus so as to produce an instantaneous regula-
tion. As on the pressing together of one or more of the contact pieces L these put
a gradually increasing additional strain on the metal strip such increase is by
preference counteracted so as to render the strain on the strip practically uniform
by placing the weighted arm G¹ at such an angle that the leverage thereof gradually
diminishes as the lever G is pressed forward against the contact pieces. The metal
strip A is by preference enclosed in a glass or other casing O, in order to preserve
it from atmospheric currents, and to make the radiation from its surface a quantity
depending only upon its own temperature, it being assumed that the outer tem-
perature of the room is practically constant.

page_text: Figs. 4 and 5 shew respectively a sectional elevation and plan of an arrangement
wherein the expansion and contraction of a thin wire A. consequent on the passing
of a greater or less current through it from the circuit wire F is caused to move a
bell-crank lever G to which it is attached so as to put less or more pressure upon
the column of carbon plates L so that by the greater or loss degree of compression
to which these plates are subjected they offer less or more resistance to the passage
of the electric current from the lever G through them to the wire F¹, and thus
produce an increase or decrease in the quantity of the electric current passing, this
arrangement being applicable for regulating small currents of high intensity. The
tension of the wire A is adjusted by the screw E.
Fig. 6 shows an elevation of an electric lamp the carbon points of which are
regulated by the expansion or contraction of a thin metal strip through which the
electric current is passed, as herein-before described. The top carbon A being the
one more rapidly consumed is mounted on a weighted slide B having a rack
gearing in a toothed wheel C, on the spindle of which is a smaller wheel C', with
which gears a rack formed on the slide D carrying the lower carbon A¹. Thus, as
the slide B with carbon A descends, by reason of its weight, it turns the gearing C, C',
and so causes the slide D and the lower carbon A¹ to ascend a proportionate distance.
The descent of B is governed by a flyer E to which rapid (rotary motion is
imparted by a large wheel C2 on the axis of C gearing with a small pinion on the
axis of the flyer. The electric current passes from the circuit wire F through
the exceedingly thin copper strip G to the insulated guide H for the slide B,
thence through the carbons A, A¹, slide D, and insulated guide I to the circuit
wire K.
The thin metal strip G is secured by a screw at its lower end, while the upper
end is attached to a toothed disc L carried by an insulated bracket, and in gear
with a tangent screw L' carried by the guide H, so that by turning the screw by
hand the disc L can be turned so as to put more or less strain on the metal strip G.
To the middle of the strip G is secured a metal piece G¹, having on one side a
stud or tooth G2 which can be made to project into the path of the flyer E so as to
arrest its motion. On the other side G¹ is in contact with a weighted bell crank
lever M which tends to press the metal strip inwards towards the flyer.
The tension of the metal strip is so adjusted by the screw L that when an
electric current of the strength due to the normal distance of the carbons is passing
through the strip the heat generated does not produce sufficient elongation of the
strip to enable the lever M to bring its stud into the path of the flyer, and,
consequently, the downward motion of the slide B not being impeded, the carbon
points are fed forward at the normal rate.
If however the carbon points approach each other to such an extent as to allow
of the passage of a larger quantity of the electric current, the metal strip in
becoming heated, and consequently expanding to a correspondingly greater extent,
is forced inwards by the weighted lever M so as to bring the stud G2 in the path
of the flyer E, the motion of which, and consequently also of the carbon points, is
thereby arrested. The carbon points continuing to be consumed, their distance
increases, and the increased resistance producing a corresponding diminution of the
current passing through, the metal strip becomes less heated and consequently
contracts, thereby withdrawing the stud G2 from the path of the flyer, and allowing
the carbons to be fed forward as before.
On the current being greatly reduced, or stopping entirely, so as to extinguish the
luminous arc, the metal strip contracts to such an extent as to bring the lever M
against a contact N, connected by a wire N' with the coil of an electro-magnet O,
which is carried by the slide D of the lower carbon, the other end of the coil being
in metallic contact with such slide. The holder of the carbon A¹ is connected to
the slide D by binged links, the lower one of which carries a soft iron armature P
opposite the core of the electro-magnet. Thus on a current being passed through
the circuit for the purpose of igniting the lamp, such current passes through the
coil of O, and this, in attracting the armature P, raises the carbon A¹ so as to make

page_text: contact with A, whereupon the current passes through the carbons and produces
the luminous arc. The heating and elongation of the metal strip G now allows the
lever M to move away from N, and the electro-magnet O being thus put out of
action, the carbon A¹ drops down into the position shewn on the Drawing.
Fig. 7 shews a sectional front view and Fig. 8 a side view of an apparatus by
which the expansion and contraction of a thin metal strip is made to record on a
paper strip the variations of the electric current passing through it.
The metal strip A is stretched over an ebonite roller C, and connected at one end
to the regulating disc B with tangent screw E, and at the other end to the spindle D
carrying a lever G with weight G', in a similar manner to the arrangement described
at Figs. 1 to 3. The lever G however in this case carries at its upper end a style G
which bears against a fixed surface Q, over which a paper strip R is made to travel
at a uniform speed from the reel R₁, so that by the expansion and contraction of
the strip A, due to the passing of a greater or less current through it, the lever G
will be moved so as to cause its style to mark a line on the paper strip R that will
indicate by its deviation from a straight line drawn by the style S the increase or
decrease of the current from the normal represented by such straight line, this being
adjusted in the first instance in such a position that when a current of normal
strength is passing through the circuit the lever G will be held by A in such a
position that the line drawn by G² will correspond with the line drawn by S.
The paper strip R is drawn forward by feed rollers T worked by worms U from
clock work V, governed by a pendulum escapement V₁, so that if the paper strip be
marked with transverse divisions indicating intervals of time, it will be seen
that the variation of the current during any intervals of time will be recorded
thereon.
It will be evident that by providing on the spindle D a second lever operating
on a series of contact pieces, arranged in combination with resistance coils in the
same manner as described with reference to Figs. 1 to 3, this apparatus may be
made to act as an automatic regulator of the current. Or the circuit wire F¹ may
be connected to any suitable rheostat of known construction, whereby the operator
can regulate the current by introducing resistances, according to the indications
given on the paper strip.
Having thus described the nature of my Invention, and in what manner the
same is to be performed, I would observe that since the filing of my Provisional
Specification I have become aware that the use of a wire or strip of metal heated
by the passage of a current for regulating the distance between the carbon points
of an electric lamp has already been described in the Specification to Lontin's
(Clark's) Patent, No. 2004 of 1877, and I do therefore not claim generally the
special application of a wire or strip of metal for this purpose, but I claim,―
First. Effecting the automatic regulation of electric currents by applying the
expansion and contraction of a metallic strip or wire forming part of the circuit to
introduce and exclude resistances.
Second. Effecting the automatic regulation of electric currents by causing the
contraction and expansion of a metallic strip or wire forming part of a circuit to
compress more or less a carbon or other conductor through which the current passes,
so as to decrease and increase its resistance.
Third. Regulating the distance between the carbon points of electric lamps or
their equivalents by the expansion and contraction of an exceedingly thin metal
strip maintained in a stretched condition, through which the current is made to pass,
means being provided whereby such expansion and contraction is caused to produce
a motion greatly exceeding the actual lengthening and shortening of the strip, so
that by such magnified motion, and by the rapid radiation of the heat imparted
to the strip, the slightest changes in the strength of the current are made to
produce an instantaneous regulation of the carbon points, substantially as herein
described.
Fourth. Arranging the metallic strip referred to in the preceding claim so that
by its contraction, consequent on the stoppage of the current, it makes contact with

page_text: '
the coil of an electro-magnet, which on the renewed passage of the current is thereby
caused to bring the one carbon point in contact with the other, so as to cause ignition
of the lamp, while by the heating of the strip the said contact is broken and the
carbon point made to resume its former position, substantially as herein described
with reference to Fig. 6 of the Drawings.
Fifth. Providing means for the adjustment of the tension of the thin metal
strip referred to in the preceding claims, so that it shall be in proportion to
the strength of current required to be transmitted, substantially as herein
described.
Sixth. Regulating the distance between the carbon points of an electric lamp by
the expansion and contraction of a thin metal strip arranged and operating as
herein described with reference to Fig. 6 of the Drawings.
Seventh. The use for regulating electric currents of apparatus arranged and
operating as herein described with reference to Figs. 1 to 5 of the Drawings.
In witness whereof, I, the said Charles William Siemens, have hereunto set
my hand and seal, this Sixth day of December, in the year of our Lord
One thousand eight hundred and seventy-eight.
Witness,
E. F. BAMBER,
12, Queen Anne's Gate,
S.W.
C. WILLIAM SIEMENS. (L.S.)