IMPROVEMENTS IN ARC REGULATOR L.AMDQ.” SP
Year: 1883

page_text: LETTERS PATENT to Rookes Evelyn Bell Crompton of the Mansion House
Buildings; Queen Victoria Street, in the City of London, Electric Engineer,
and Tom Crabb of Arc Works, Chelmsford, in the County of Essex, Engineer:
for an Invention of "IMPROVEMENTS IN ARC REGULATOR L.AMDQ.”
PROVISIONAL SPECIFICATION left by the said Rookes Evelyn Bell
Crompton and Tom Crabb at the Office of the Commissioners of Patents on
the 22nd May 1883.
ROOKES EVELYN BELL CROMPTON of the Mansion House Buildings Queen
Victoria Street in the City of London Electric Engineer and TOM CRABB of Arc
Works Chelmsford, in the County of Essex Engineer "IMPROVEMENTS IN ARC
REGULATOR LAMPS
+
"
Our invention relates to that part of the mechanism of Electric arc Regulator
lamps which controls the approach towards one another of the carbon Electrodes.
In one form of it we substitute for the rack rod or clutch rod (generally used
to carry the upper carbon) a tube with a slot cut in one side of it-which we
hereafter call the slotted tube.
:
This slotted tube is arranged in the usual manner, well known to those
accustomed to this kind of mechanism. It is fitted at its lower end with a carbon-)
holder, and is arranged to slide freely and truly through holes or guides in a
framework of convenient form.
The longitudinal slot is cut on one side of it for a sufficient length to allow of
the travel the tube, is intended to make so as to provide for the use of carbon rods
of the desired length.
it
In this slotted tube we arrange a short tube or sleeve sliding fairly along
on this sleeve we mount a spindle or axis free to revolve this axis being at right,
angles to that of the tube
This spindle carries a pulley of such diameter that one point in its periphery
passes within the tube through the slot and coincides sufficiently nearly with the
axis of the tube, that it allows of a cord stretched in the line of this axis to
engage with the pulley by making one or more complete turns round it.
It is evident that if the stretched cord be fixed relatively to the slotted tube
any sliding movement of the latter in a longitudinal direction through the sleeve
can only take place by allowing the pulley which is geared with the cord to revolve
and so roll along the cord or vice versa
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So long as the pulley is prevented from revolving so long will the tube be
retained in a fixed position relatively to the sleeve.

page_text: We mount on the same spindle as the pulley in preference-two or other suitable
number of discs (of large diameter comparatively to the pulley)
One on each side of the slotted tube or otherwise. and these discs being made of
the same diameter we so arrange a vibrating lever, hinged or pivotted to the
framework of the lamp, that this lever takes the weight of the slotted tube and
carbon, sleeve, pulley, and discs-Normally, the weight is carried on the discs-
as their peripheries rest on the upper surface of the lever when it is in its
normal position.
But we also arrange an adjustable stop or finger on the sleeve so placed that a
slight movement of the vibrating lever from its normal position will transfer the
weight of tube, sleeve and parts from the disc to this finger.
Then the peripheries of the discs being no longer in contact with the surface of
the lever are free to revolve-and thus allow the slotted tube to descend through
the sleeve until such time as the vibrating lever returns to its normal position
causing the weight to be retransferred to the peripheries of the discs and thus
arresting the movement of the slotted tube through the sleeve.
The length of arc of vibration through which the lever must vibrate to effect
the above described movement is regulated by the relative distances from the
pivot or fulcrum of the lever of the two bearing points on its upper surface-viz.
1st That of the peripheries of the discs
2nd That of the finger on the sleeve
We can also employ one disc-in place of the two discs-If we place the disc
centrally and have pulleys and cords at each side of it-The slotted tube can then
take the form of a pair of side rods.
Or we can obtain the same movement by the use of toothed gearing by cutting
teeth on a central rod or on two side rods thus forming them into rack rods) and
substituting for the pulley or pulleys pinions having teeth to engage with the
rack or racks The other parts of the arrangement being substantially the same
as that first mentioned
It will readily be understood by those accustomed to this class of mechanism;
That we can obtain all the movements required in a regulating arc lamp-by
attaching to the vibrating lever any of the well known Electro-magnetic
contrivances wound simply or differentially such as those referred to in the
Specifications of Letters Patent granted to me the said Rookes Evelyn Bell
Crompton N° 346 January 24th 1882 and 3339, July 14th, 1882.
It is also evident that we can mount more than one slotted tube with its
mechanism (or any of the equivalents of the slotted tube hereinbefore mentioned)
on one vibrating lever so as to be able to burn two or more pairs of carbons in
rotation in one lamp without materially increasing the complication of parts and
cost of the lamp
We effect this by making the relative distance of the two bearing points
(namely 1 that of the peripheries of the discs. 2nd that of the fingers of the sleeves)
above referred to, differ slightly for each slotted tube and its mechanism in such a
manner that the vibrating movement of the lever affects each slotted tube et cetera
in rotation as we may desire it.
We sometimes roughen the peripheries of the discs and in some cases we add
one or more gearing wheels so as to obtain greater relative movement of the
peripheries of the discs to that of the slotted tube through the sleeve.
We sometimes obtain additional regulating power by utilizing the adjustable
finger above described as a contact piece whereby at the moment of contact of the
finger, the whole or a portion of the wire of the electro magnetic circuit whether
it be of the main circuit or a derived circuit (the latter being commonly called the
shunt) can be cut out and thus the electro magnetic action modified or otherwise
affected or we can in place of this attach to the vibrating lever additional, a finger
or fingers to act as a contact piece or pieces and thus effect the same object

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said Rookes Evelyn Bell Crompton and Tom Crabb in the Great Seal
Patent Office on the 19th November 1883.
ROOKES EVELYN BELL CROMPTON of the Mansion House Buildings Queen
Victoria Street in the City of London Electric Engineer and TOM CRABB of Arc
Works Chelmsford in the County of Essex, Engineer. "IMPROVEMENTS IN ARC
REGULATOR LAMPS."
:
Our improvements relate to that part of the mechanism of Arc Regulator lamps
which controls the approach towards one another of the carbon electrodes.
We hereafter call the rod or sliding holder which carries one or other of the
carbons the "rod."
;
We call the movement of approach of this rod "the Feed movement.",
We call a vibrating lever, which is worked by a solenoid, or other similar electro
magnetic device well known to those accustomed to this class of mechanism, the
"lever."
Our improved apparatus for controlling the feed movement of the rod consists in
gearing to it either by means of a cord, chain, or toothed rack, a pulley or pinion
hereafter called "the pinion"
ر
'
Fixed to the axis of this pinion is mounted one, or more discs, or wheels,
of diameter considerably greater than that of the pinion itself, in such manner that
if the pinion with its discs is prevented from revolving, the rod cannot make a
feed movement.
These wheels, or discs, we hereafter call the "discs "
We so place a vibrating lever that in one position of its arc of vibration the
pressure of the rod with its pinion and discs is wholly, or partly, borne by a support
finger or arm connected with the axis of the pinion. The point on the lever on
which the pressure is carried we call "y."
33
In another position of the are of vibration of the lever the pressure of the discs
is partly or wholly transferred from the point y connected with their axis, to a
point on the surface of the lever which presses firmly against their peripheries
The discs can revolve with more or less freedom, and thus allow the rod to make
a feed movement accordingly as the pressure is transferred from the point y to the
point x.
Figures 1. 2. 3. 4. 5. 6 and 7. show diagramatically in side view various modes of
combining the rod pinion discs and lever in order to accomplish the controlling
movement above described.
:
In Figure 1 the rod a a takes the form of a tube with a long slot cut on one
side of it. Within this tube is stretched a cord b b geared to the pulley'c by,
passing once round it. The end is kept tightly stretched by the spring d. e e is a
sleeve carrying the axis of the pulley through which the tube a, a, can slide
freely. ffis the farther of two discs mounted on the same spindle as the pulley c...
The nearer disc being removed to show, the mechanism. 9 is the vibrating lever
pivotted at the point A its vibrations are controlled by the solenoid or electro
magnetic device B. h is the arm or support bearing on the upper surface of the
lever at the point y.
The peripheries of the disc also bear on the upper surface of the lever at the
point x.
In this diagram the pressure is shown equally distributed between the points OC
and y and this is the normal position of the lever.
When the solenoid allows the free end of the lever y to descend, and a part of
the pressure which before the movement was transmitted to the lever at the point
s

page_text: to be transferred to the point y the peripheries of the discs being partially freed from
pressure at the point x will be free to revolve in the direction of the arrow and
allow the rod a a to descend through the sleeve e so as to give a feed movement to
the carbon.
When the carbons have approached sufficiently closely, the controlling solenoid B. 5
recommences to draw in its core thus lifting g, and transferring the weight to the
point arrests the movement of the rod through the sleeve.
Figure II shows a similar arrangement, but in place of the slotted tube we use a
rod a a with a rack cut on one side of it gearing into the pinion c, the discs ff
being fixed to the spindle of the pinion as before, it is evident that this arrangement
will work precisely as that last described.
Figure III shows a third arrrangement the descending carbon holder may either
take the form of the slotted tube as in Figure 1, or the rack rod. as in Figure II,
the rest of the arrangements being the same but with this difference that the
peripheries of the discs instead of being smooth have on them equivalent projections
such as pins or teeth, this allows the lamp to feed each time the exact distance
between two consecutive projections or pins on the discs.
In this case it is evidently not necessary for the whole, or even any part, of the
pressure to be taken by the lever at the point x in order to prevent the revolution
of the discs and consequent feed. movement. any pressure that then may be at the
point takes the form of frictional side pressure of one of the projections, or pins,
on the disc against the point x which may conveniently be constituted by a pallet,
or stop, of hard material.
t
Figure IV shows another arrangement. In this case the lever g is pivoted on the
sleeve at the point of pressure y. At the bearing point x a spiral, or other spring,
is interposed between the bearing point on the lever and the periphery of the discs,
the lever g is pivoted to the main frame of the lamp at the point A, but as it is
necessary in this case to give the lever some side play the pivoted point is slotted
longitudinally in regard to the lever as shewn on the diagram. The free end of
the lever being controlled by the solenoid B as before. The action is precisely the
same as that before described, when the lever is in its normal position as shewn in
the diagram the weight of the moving parts is distributed between the points
and y. but when the free end of the lever descends, a portion of the weight borne
at the point is transferred to the point y, and the discs being free to revolve the
feed movement can take place as before
Figure V shows an arrangement the discs being placed underneath the lever
which instead of being pivoted at a fixed point on the frame, is pivoted at the
point y on the sleeve and so long as the lever is in firm contact with the peripheries
of the discs at the point a the lever rises and falls with the tube and sleeve
without any movement relative to them but when the whole is allowed to descend
sufficiently to admit of the point k coming in contact with the stop A fixed in the
frame of the lamp, then part of the weight will be taken at this point A and the
lever will vibrate on the point y, as a centre, and thus free the periphery of the
discs at the point x.
The feed movement will take place as before.
Figure VI shows an arrangement in which the pressure at both bearing points x
and y is taken on the peripheries of the discs ff as before described.
When the pressure is taken at the point x the feed movement is arrested, but
when the pressure is transferred to the point y the discs bear on the freely revolving
roller q placed at y in such manner that the discs can revolve and the feed
movement take place as before.
Figure VII shews the mechanism adapted to a focussing lamp.
In this case the lower carbon holder, or rod, a a is pulled upwards by the weight
of the upper carbon holder b b by means of the flexible cords in the manner shewn
The vibrating lever is pivoted at the point A and the disc f. f is pressed up
against the underside of it. The lower carbon holder a a has a rack cut on it
into which the pinion c gears as in Figure II. The support, or arm, h bears

page_text: against the lever at the point y and the discs ff bear against it at the point x in
this case it is necessary to insert a spring m to sustain the weight of the sleeve,
discs, and other parts the solenoid B controls the free end of the lever as before.
In the arrangements shewn by Figures 1. 2. 3. 4. 5. 6 and 7 the separation of
the carbons, or, what is usually known as "striking the arc" is performed by the
direct lift of the solenoid, or electro magnetic device, acting on the lever and in the
case of a double lamp the arc is struck between one pair of carbons in advance of
the other pair by causing the finger h belonging to that pair of carbons to be
longer than that belonging to the second pair.
"
But on diagram Figure VIII we show an arrangement differing slightly from
that shewn on diagram Figure VI,-in this particular-that, part of the action of
"striking the arc is carried out in a different manner. In this case we prefer to
make the lever g¹ g² à lever of the first order the end g¹ taking the form of a cam
curved as shewn in the diagram or in such manner that when the end g² of the
lever g' g² is moved in the direction of the arrow the peripheries of the discs ff
being firmly in contact with the curved surface of the cam at the point x engage
gear or roll on it, and so cause the rod to rise within the sleeve; at the same time
the sleeve itself is bodily lifted through a short space, a reversed movement allows
the sleeve itself to descend as well as the rack to slide through it and when the
arc of vibration extends to such a point that the free rollers mounted in the ends
of the arm h take part of the pressure then the peripheries of the discs ff being no
longer firmly in contact with the curved surface of the cam will be free to revolve
as described in respect of diagram VI and the feed movement take place as before.
Figure IX shows a double lamp complete, in which this our invention is applied;
the upper carbon holder a a in this case take the form of rack rods, descending
through the sleeves e e. ff are the controlling discs, and g g the vibrating levers:
hh the arms, or supports.
B is the controlling solenoid wound with coarse wire at B¹ and with fine wire
at B2. p shows a spiral spring the use of which is to partially support the weight
of the carbon-holders, carbons, sleeves, rack-rods, and other vibrating parts. At t
is shewn the contact piece by which the lamp is cut out of circuit whenever the
levers are in their lowest position and the contact piece t rests on the end of the
negative rod 8 8 which is insulated from the body of the lamp
The other arrangements will be readily understood by those accustomed to this
class of mechanism.
Having thus described our invention and means adapted for carrying the same
into practical effect we would have it understood that we do not confine ourselves
to the precise details indicated But what we do claim is the adaptation or combina-
tion of parts for regulating the approach or distance apart of the carbon electrodes
of arc regulator lamps, substantially as and for the purposes herein described and
shewn in the accompanying drawings.
In witness whereof we the said Rookes Evelyn Bell Crompton and Tom Crabb
have hereunto set our hands and seals this Thirteenth day of November in the
year of our Lord One thousand eight hundred and eighty three: