Improvements in Electric Arc Lamps or Lighting Apparatus.
Year: 1895

page_text: Date of Application, 24th Dec., 1895
Complete Specification Left, 23rd Sept., 1895-Accepted, 14th Nov., 1896
PROVISIONAL SPECIFICATION.
Improvements in Electric Arc Lamps or Lighting Apparatus.
I, WILLIAM HENRY SMITH, of Upton Villa, Penge, in the County of Surrey,
Engineer, do hereby declare the nature of this invention to be as follows:-
My invention relates to electric arc lamps or lighting apparatus, and its objects
are to improve and simplify the construction of the same, to make them more
reliable in action, and to ensure the steadiness of the light.
My said invention comprises an improved regulator for maintaining the required
relative position of the carbons. And my said invention also comprises other
improvements hereinafter mentioned.
The regulators generally employed in electric arc lamps contain clockwork or other
more or less delicate and complicated mechanism, comprising brakes, springs,
dash-pots and the like, which is liable to get out of order or to have its motion
easily arrested or retarded by dirt or foreign bodies getting into it. Moreover, in
some of such regulators, solenoids are used merely for controlling the movements
of the mechanism, whilst the regulators wherein the solenoids themselves effect the
required movements of the carbon or carbons, are usually very sensitive to variations
or fluctuations of the current.
Now I provide a regulator whereby the feeding of the carbon or carbons is very
efficiently performed without the aid of such delicate or complicated mechanism, and
which feeding is very slightly affected by ordinary variations or fluctuations of the
current. My improved regulator is very reliable in its action, can easily be repaired
and is not readily affected by dirt or damp.
In my improved regulator, I employ a solenoid or solenoids each having a movable
core, and I connect the said movable core or cores with the carbon or carbons
through the medium of grooved wheels or pulleys or levers and cords or chains, or
their equivalents, in such a manner that any movement of the said core will cause
the movement of the carbon or carbons through a much greater distance. By this
arrangement I ensure that, whilst a steady pull of the solenoid upon its' core
sufficient to overcome the inertia of the parts will effect a corresponding movement
of the said parts, a pull of like force applied suddenly and momentarily will not
move the carbon or cartons through a sufficient distance to cause any sensible
variation in the light produced.
I find it advantageous to construct my regulator as follows, viz. :-I mount a
grooved wheel or pulley of comparatively large diameter on a shaft carried in
suitable bearings in the frame of the lamp, and I suspend the carbon-holders from
the two ends of a cord, band, or chain passed over the said wheel or pulley, such
cord being secured, to avoid slipping, at a suitable point on the wheel or pulley.
On the said shaft I also mount two smaller grooved wheels or pulleys, and I pass
over and secure to each of the smaller pulleys a cord or chain, from the free end
of which is suspended the movable core of a solenoid. One of these solenoids is
arranged in the main circuit and the other is arranged in a shunt-circuit, in the
well-known manner.
By this form of construction I greatly diminish the number of parts in the
regulator and reduce the friction, whilst ensuring greater steadiness of the light.
I can, if desired, still further increase the steadiness of the light by augmenting the
inertia of the moving parts, such as the shaft and grooved wheels, by increasing

page_text: their weight, or by increasing the difference in diameter of the larger and smaller
pulleys.
According to another part of my said invention, I make the guide-rods for the
carbon-holders thin and wide, and arrange them with one of their thin edges towards
the carbons, so that each of them will serve efficiently for guiding one of the carbon-
holders in its up and down movements, and will, at the same time, prevent lateral
movement of such carbon-holder; I thus obviate the necessity for guiding each
carbon-holder by means of both guide-rods. And 1 gain the further advantage that
the said guide-rods will cast but little shadow. I also make the bar connecting the
said guide-rods at their lower end flat so as to diminish as much as practicable the
shadow cast thereby. I prefer to make the narrow edges of the said guide-rods
V-shaped and their sides hollowed out, so that, although the supports of the carbon-
holders will bear only against the V-shaped parts of the said guide-rods, there will
be no liability to lateral movement of the carbon-holders, and any dirt that may
gather on the sides of the guide-rods will not readily obstruct the movement of the
carbon-holders.
Carbon-holders are usually provided with a hole or socket to receive the carbon
and with a set-screw to bear against the carbon and secure it in place; but with
such an arrangement, when a carbon is burnt out, it cannot be conveniently replaced
until the holder has been allowed to cool, and it often happens that it is difficult to
place the carbons symmetrically. To obviate these inconveniences I provide an
improved carbon-bolder which is made in two halves or parts having V-shaped
jaws, so that, when the carbon is clamped between them, they will bear against
the same on four sides thereof, and which is constructed as hereinafter mentioned.
According to one method of constructing the carbon-holder which is insulated from
the frame, one half of this carbon-holder is made with a lateral extension which
embraces one of the guide-rods but is out of contact therewith, and which is secured
to the support for the carbon-bolder, but suitably insulated therefrom. The other
half of the said carbon-holder is made with a strap which surrounds or embraces
the first half of the holder and its lateral extension, and which is provided at its
outer end with a set-screw that bears against the outer edge of the said lateral
extension. With this form of holder, the carbon can be easily replaced immediately
it is burnt out, as the set-screw securing it will always remain cool enough to be
conveniently manipulated. The inner half of the other carbon-holder is formed on
the corresponding support and the outer half thereof embraces the inner half and the
corresponding guide-socket, the set-screw bearing against the said socket. I prefer-
ably form the strap and the outer half of the corresponding holder from one solid
piece of metal, which I open out to admit of its being passed over the inner half of
the holder and its extension, or the said guide-socket as the case may be, and then
close it in so that it fits freely in grooves in the sides of the said inner half of the
carbon-holder.
According to another arrangement I make both halves of the said carbon-holder
with lateral extensions which are secured to but insulated from the support for the
said holder and are provided with a set-screw whereby they may be brought towards
each other to clamp the carbon between them.
For the purpose of controlling the movement of the carbons in striking the arc,
I provide a very simple and effective stop or clutch, which is arranged on one of
the guide-rods for the carbon-holders. This stop or clutch is adapted to rest upon
one or more pins or studs or other suitable projections on the support of the carbon-
holder, so that, when the carbon is raised to strike the are, the said stop or clutch
will be tilted and caused, when the carbon has been moved through the required
distance, to grip the said guide-rod and thereby arrest the movement of the said
carbon. In some cases the said stop or clutch is made with a spring to rest upon
the pins or studs so as to permit the required movement of the carbon to strike the
arc. This stop or clutch is easily accessible and can therefore be readily held out of
action to permit free movement of the carbon-holders when replacing or adjusting
the carbons.

page_text: I also provide improved means for supporting the globe of the lamp whilst
permitting the ready removal and replacement thereof. For this purpose, when the
regulator is arranged above the carbons, I employ a metal cover or casing for the
said regulator, and I attach the globe thereto by spring hooks engaging with a
circular flange so that they can be caused to engage therewith whatever be the
position of the globe when raised into its normal position. For example 1 provide
the said cover or casing with a turned-up flange or annular piece, and to the metal top
or coronet on the globe I attach spring hooks adapted to engage with the said
annular piece or flange and provided with handles whereby, when the globe is
slightly raised, they can be easily moved outward and held out of engagement with
the said flange while the globe is being lowered. These handles also serve for
.holding up the globe while disengaging and raising or lowering it. The said
spring hooks are preferably provided with set-screws or other suitable devices
whereby they may be secured so as to prevent their accidental disengagement from
the said flange.
In some instances I adapt my improved regulator to lamps in which only one of
the carbon-holders is movable.
In some cases I find useful or advisable to transmit the motion or pull of the
solenoids on their cores to the carbons by means of racks and pinions instead of
by pulleys and cords.
Dated the 24th day of December 1805
D. YOUNG & Co.,
11 & 12 Southampton Buildings, London, W.C.,
Agents for the Applicant.
I, WILLIAM HENRY SMITH, of Upton Villa, Penge, in the County of Surrey,
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:-
My invention relates to electric are lamps or lighting apparatus, and its objects are
to improve and simplify the construction of the saine, to make them more reliable in
action and to ensure steadiness of the light.
The regulators generally employed for maintaining the required relative position of
the carbons in electric arc lamps, contain clockwork or other more or less delicate
and complicated mechanism (comprising brakes, springs, dash-pots or the like) which
is liable to get out of order or to have its motion easily arrested or retarded by dirt
or foreign bodies getting into it. Moreover, in some of such regulators, solenoids
are used merely for controlling the movements of the mechanism, whilst others,
wherein the solenoids themselves effect the required movements of the carbon or
carbons, are usually very sensitive to variations or fluctuations of the current.
Now I provide a
regulator whereby the feeding of the carbon or carbons will be
efficiently performed without the aid of such delicate or complicated mechanism, and
the light will be very slightly affected by ordinary variations or fluctuations of the
current. My improved regulator is very reliable in its action, can easily be repaired,
and is not readily affected by dirt or damp.
In my improved regulator, I employ a solenoid or solenoids each having a movable
core, and I connect the movable core or cores with the carbon or carbons through the
medium of grooved wheels or pulleys or levers and cords or chains, or their
equivalents, in such a manner that any movement of the said core or cores will
cause a greater movement of the carbon or carbons. By this arrangement I ensure
that, whilst a steady pull of either solenoid upon its core, sufficient to overcome the

page_text: inertia of the parts, will effect a regular and steady movement of the carbon or
carbons, a pull of greater force applied suddenly and momentarily will not move the
carbon or carbons through a sufficient distance to cause any sensible variation in
the light produced.
I find it advantageous to make my improved electric arc lamp or lighting apparatus
with the two carbon-holders suspended from opposite sides of a grooved wheel or pulley
or its equivalent, and to employ for regulating the movements of the carbons two
solenoids one in series with the arc and the other in a shunt-circuit, the cores of
which solenoids are positively connected with the said pulley or its equivalent in such
a manner that any movement of either core will cause the movement of the carbons
through a greater distance.
And
If desired, I can dispense with the shunt-coil, and depend upon the extra weight
of the upper carbon and carbon-holder for effecting the feeding of the carbons.
in such case I can, if desired, use more than one solenoid in series with the arc and
so arranged that the cores of such solenoids will act in the same direction for the
purpose of striking the arc; this arrangement may be found advantageous for single
lamp circuits. Or I can use one or more solenoids each differentially wound with
both a series coil and a shunt coil.
My said invention, moreover, comprises other improvements hereinafter set forth.
In the accompanying drawings:-
Figure 1 is a front elevation, partly in vertical section, of an arc-lamp constructed
according to my said invention.
Figure 2 is a side elevation, partly in vertical central section on the line x, x,
Figure 1.
Figure 3 is a plan or top view, some of the parts being removed.
Figure 4 is a horizontal section on the line x, x Figure 1, looking from beneath.
Figure 5 is a side elevation, drawn to an enlarged scale, of the upper carbon-
holder and the sliding support for the same.
Figure 6 is a plan, partly in section on the line x², a², Figure 5, and
Figure 7 a section on the line ³, ³, Figures 5 and 6.
Figure 8 is a side elevation, also drawn to an enlarged scale, of the lower carbon-
holder and the sliding support for the same.
Figure 9 is a plan, partly in-horizontal section on the line 4, 4, Figure 8, and
Figures 10 and 11 show, in side elevation and plan respectively, a modified form
of clutch hereinafter described.
Like letters indicate corresponding parts throughout the drawings.
A is a casting on which the series regulating coil B, the shunt regulating coil C,
and other parts are mounted, the supporting ring or hook D being attached thereto
by two standards a and a cross-bar a¹.
F, G are the carbon-holders, which are suspended from the two ends of a cord,
band or chain H passed over a wheel or pulley E, which is fixed on a shaft c
supported by adjustable pivots d in the standards a, such cord, band or chain being
secured, to avoid slipping, at a suitable point on the wheel or pulley E. On the
shaft c are also fixed two smaller grooved wheels or pulleys J, K, and passing over
and secured to each of these smaller pulleys is a cord or chain, e, f, from the free
end of which is suspended a movable core e',', controlled by the corresponding
solenoid B, C.
The carbon-holders F,,G are mounted on sliding supports F', G', to which are
attached the two ends of the cord H respectively, and which are arranged to slide
up and down upon guide-rods L. I make these guide-rods thin and wide, and secure
them to each other and to the other parts of the lamp-frame in such a manner that one
of their thin edges is towards the carbons; each of the said rods will, therefore,
serve efficiently for guiding the corresponding carbon-holder in its up and down
movements and will, at the same time, prevent lateral movement of such carbon-
holder; I thus obviate the necessity for guiding each carbon-holder by means of
both guide-rods. And I gain the further advantage that the said guide-rods will
cast but little if any shadow and will not obstruct the light emitted by the arc like

page_text: the guide-rods ordinarily used. I also make the bar 9 connecting the said guide-rods
at their lower end flat and thin so as to diminish as much as practicable the shadow
cast thereby. The sides of the guide-rods L are hollowed out as shown in Figures 6
and 9, so that, although the supports of the carbon-holders will bear only against
the V-shaped or other edges of the said guide-rods, there will be no liability to
lateral movement of the carbon-holders, and any dirt that may gather on the sides
of the guide-rods will not readily obstruct the movement of the carbon-holders.
Instead of making the carbon-holders as usual with a hole or socket to receive
the carbon and with a set-screw to bear against the carbon and secure it in place,
I make each carbon-holder in two halves or parts F2, F³ or G2, G3, having jaws
which are preferably V-shaped so that, when the carbon is clamped between them,
they will bear against the same on four sides thereof. The upper carbon-holder F,
Figures 5 to 7, is insulated from its sliding support F1 by means of pieces k of
vulcanized fibre or other suitable material, and the part F' is formed with an
aperture F sufficiently large to clear the guide-rod L, which aperture can, if
desired, be lined with suitable insulating material. The part G³ of the lower carbon-
holder G is attached to or formed integrally with its sliding support G¹. The outer
part For G³ of each carbon-holder is made in the form of a strap which surrounds
or embraces the part F2 or G2, and slides in grooves m formed in the sides of the
jaw, and between projections m¹ on the sides of the part For G; each strap F³ or G³
is provided at its outer end, that is to say, outside the corresponding guide-rod L,
with a set-screw n that bears against the outer edge of the part For G³, and whereby
the jaws may be drawn together to tightly clamp the carbon. With carbon-holders
of this form, the carbons can be easily replaced symmetrically immediately they are
burnt out, without waiting for the parts to cool, as the set-screws n securing them
will always remain cool enough to be conveniently manipulated. Each of the said
straps is preferably formed from one solid piece of metal, which is opened out to
permit of its being passed over the inner part F2 or G³, and is then closed in so that it
fits freely in the grooves m in the sides of the latter and between the projections m¹.
A stop or clutch M is arranged on one of the guide-rods L and rests in an inclined
position upon a pin p fixed in one side of the sliding support F' of the upper carbon-
holder. This clutch, when in a horizontal or approximately horizontal position,
can be slid freely up and down upon the guide-rod L, but when tilted, for example,
by upward movement of the carbon-holder F and pin p, it will bind on the sides of
the guide-rod L, and prevent further upward motion of the said holder.
The electrical connections of the lamp are as follows:-Starting from the insulated
terminal r, the current passes by a flexible conductor to a terminal on the
strap F3 of the insulated carbon-holder F, thence, to the lower carbon-holder G
through the arc, and via the corresponding guide-rod L and frame A to the end B¹
of the series coil B, as shown in Figure 2°; the current then passes through the said
series coil to the insulated terminal s. The shunt-circuit extends from the terminal r,
through the shunt or high resistance coil C to the terminal s. Other suitable
electrical arrangements may be made; for example, the lamp may be provided with
an automatic cut-out for series working.
When the electric current is first allowed to pass through the lamp, the series
coil B being energized pulls down the core e' and thus strikes the arc by simultaneously
raising the upper carbon and lowering the lower carbon, the stop or clutch M
arresting the movement of the parts when the arc is of the proper length. When
through the consumption of the carbons the resistance of the arc is increased, the
shunt-coil C becomes the stronger and by exerting a steady downward pull upon the
core feeds the carbons towards each other, the core e' being drawn outward as
the core is drawn into its solenoid, and vice versa.
It will be seen that by. reason of the multiplication of the motion through the
medium of the grooved wheels or pulleys E, J, K, any movement of either
core e or will effect the movement of the carbons with their holders through a
greater distance, and by reason of this fact, a steady pull of either coil upon its core
will effect a regular and steady movement of the carbons, whilst, should a sudden and

page_text: momentary increase take place in the force exerted by either coil upon its core, such
increase of force will be absorbed or nearly absorbed before it has overcome the
inertia of the moving parts. Therefore the steadiness of the light will not be liable
to be unduly affected by sudden or rapid variations or fluctuations of the current.
By this form of construction I greatly diminish the number of parts in the
regulator and reduce the friction, whilst ensuring greater steadiness of the light.
I can, if desired, still further increase the steadiness of the light by augmenting the
inertia of the moving parts, such as the shaft c and grooved wheels E, J, K, by
increasing their weight, or by increasing the difference in diameter of the larger and
smaller pulleys.
.As above stated. I can, if desired, modify the number and arrangement of the
solenoids for regulating the movements of the carbons.
I sometimes find it useful or advisable to transmit the notion or pull of the
solenoids on their cores to the carbons through multiplying gear comprising racks
and pinions instead of pulleys and cords.
In some instances adapt my improved regulator to lamps in which only one
of the carbon-holders is movable.
In Figures 10 and 11 I have shown a modification of my improved stop or clutch,
in which the part M' is adapted to engage with a pin p on one or both sides of the
support F, and is connected to the body M of the stop or clutch by means of a
spring M², the relative motion of the body M and part M' being limited by means
of an adjustable bolt q, whereby the length of the arc can be regulated as desired.
The body M engages with the guide-rod L of the lamp, and the spring M³ permits
the part M¹ to be moved up to the body M in the striking of the arc.
•
My improved stop or clutch easily accessible and can therefore be readily held
out of action to permit free movement of the carbon-holders when replacing or
adjusting the carbons.
For supporting the globe of the lamp whilst permitting the ready lowering,
raising and fixing thereof, in cases where the regulator is arranged above the carbons,
I employ a metal cover or casing for the said regulator, and I attach the globe
thereto by spring hooks engaging with a circular flange so that they can be caused
to engage therewith whatever be the position of the globe when raised into its normal
position. For this purpose the cover or casing N is provided with a turned-up
flange or annular piece P, and to the metal top or coronet Q on the globe, I attach
spring hooks R. adapted to engage with the annular flange P and provided with
handles R' whereby, when the globe is slightly raised, they can be easily moved
outward and held out of engagement with the said flange while the globe is being
lowered. These handles also serve for holding up the globe while disengaging
and raising or lowering it. The said spring hooks are provided with set-screws t
or. other suitable devices whereby they may be secured so as to prevent their
accidental disengagement from the said flange. Suitable chains or the like are
provided for sustaining the globe when lowered.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed, I declare that what I
claim is
First. An electric arc-lamp or lighting apparatus, in which the movable core or
cores of a regulating solenoid or solenoids are positively connected through
multiplying gear with the carbon-holder or carbon-holders so that any movement
of the said core or cores will cause the movement of the carbon-holder or carbon-
holders through a greater distance than that traversed by the core or cores, for the
purposes above specified.
Second. An electric arc lamp or lighting apparatus in which the carbon-holders
are suspended from opposite sides of a pulley or its equivalent and their movements
are regulated by one or more solenoids the core or cores of which are positively
connected with the said pulley or its equivalent, substantially as hereinbefore
described and for the purposes specified.

page_text: Third. The combination, with the upper carbon-holder, of one or more solenoids
the movable core or cores of which are positively connected through multiplying
gear with the said carbon-holder, substantially as and for the purposes above specified.
Fourth. In an arc-lamp, a stop or clutch arranged to slide on the guide-rod for
the upper carbon-holder and to engage with a pin or pins attached to the said
carbon-holder, substantially as and for the purposes specified.
Fifth. A sliding stop or clutch provided with an engaging arm or arms attached
thereto by means of a spring, and with a stop for limiting the motion of the said
arm or arms relatively thereto, substantially as and for the purposes specified.
Sixth. A carbon-holder comprising two halves or parts provided with suitable
jaws, one of the said halves or parts extending around the other and being adjustable
relatively thereto by means of a set-screw or the like, substantially as herein before
described and for the purposes specified.
Seventh. An electric are lamp or lighting apparatus in which the guide-rods for
the carbon-bolders and the bar connecting the said guide-rods are made thin and
wide substantially as described with reference to the accompanying drawings, for
the purposes specified.
Eighth. The improved arc-lamp or lighting apparatus constructed substantially
as described with reference to the accompanying drawings, and operating as and for
the purposes above specified.
Dated this 23rd day of September 1896.
W. H. SMITH.
D. Young & Co.,
11 & 12 Southampton Buildings, London, W.C,
Agents for the Applicant