An improvement in Electric Arc Lamps
Year: 1895

page_text: Date of Application, 1st Jan., 1895
Complete Specification Left, 20th Mar., 1895-Accepted, 27th Apr., 1895
An improvement in Electric Arc Lamps
I WALTER STEVENS of 61 Rosebery Avenue Clerkenwell in the County of
Middlesex Electrician do hereby declare the nature of this invention to be as
follows:-
My invention relates to means of automatically regulating the distance of the
carbons of an electric arc lamp the objects of which I have in view being simplicity,
cheapness of construction certainty of action and the short length of lamp. For
this purpose 1 make the top carbon holder in the form of a rack which gears into
the centre pinion of the friction wheel the pivot or axis of the said wheel is carried
or mounted on a pivoted lever or rocker. The top carbon holder being connected
by cords or chains over pulleys or in any other suitable manner or I may carry the
said cords or chains directly over the centre of the said friction wheel thus
dispensing with the long rack or top carbon holder and getting the action or
movement of the carbon through the agency of the cords or chains thereby making
At the
the lamps length considerably shorter than would otherwise be the case.
free end of the said rocker is pivoted a brake which works against the outside of
the wheel the long or free end of the said brake carries a regulating screw for the
At the same end of the lever or rocker
purpose of adjusting or freeing the brake.
is carried a weight or spring and a soft iron coil which is acted upon by the current
flowing through a solenoid which encircles the said coil.
The action of the lamp is explained as follows:
The current entering the coil (which is in shunt of the carbons) attracts the
coil this being connected directly with the lever or rocker pulls the rocker friction
wheel brake and top carbon holder with it thus lowering or bringing the top carbon
at the same time raising the bottom carbon thereby bringing them in contact and
striking the are the said spring or weight opposing the force solenoid thus
separating the carbons at the moment of the arc being struck by reason of the
rocker and friction wheel and carbon holder being raised the said rocker is now
held or balanced between the two forces that of the spring or weiglit and the
attractive force of the solenoid upon its coil. The friction wheel at this stage
is locked or held fast by the brake. Upon the are slightly increasing in length
greater tension or force is created in the shunt coil or solenoid thus attracting the
coil and pivoted rocker which carries the brake and friction wheel. The free end
or adjusting screw of the said brake now comes in contact or rests ou a fixed part
or anvil thus raising it somewhat and allowing the friction wheel to slightly revolve
thereby shortening or bringing the arc to its normal length the tension or force
of the solenoid' is now lowered the spring or weight predominating thus slightly
raising the rocker wheel and brake thereby easing the free end of the brake from
off the anvil thus locking or fixing for the time being the top carbon holder leaving
the same thing to be repeated upon the arc increasing in length or burning away.
Dated this 1st day of January 1895.

page_text: да ортоусте 2-битото нашую.
I WALTER STEVENS of 61 Rosebery Avenue, Clerkenwell in the County of
Middlesex Electrician 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 said invention relates to means for automatically regulating the distance 5
apart of the points of the carbons of an electric arc lamp and the object of such
invention is to enable a lamp of the nature before described to be constructed in
a more simple manner and at a less cost than hitherto and also that there shall be
certainty in the action of the lamp and it shall not be of undue length..
In describing my invention I shall refer to two sheets of drawings accompanying
this Specification, and to the figures and letters of reference thereon. Sheet 1
Figure 1 shewing a front view of an electric arc lamp fitted with my improved
regulating devices and on Sheet 2 by Figure 2 1 shew a portion of the former
figure with the mechanism acting under differcut conditions and by Figure. 3: the
reverse of Figure 2.
In carrying out my invention I construct that portion of the lamp carrying the
carbons after the fashion of the well known. Brockie Pell lamp the lower carbon. A
being carried in a socket A¹ supported by a crossbead or platform A³ having
guides AA³ embracing or free to slide on standards or uprights A. A and
connected to the socket B' carrying the upper carbon B by a chain C passing over
a pulley D or any other suitable means may be employed for this purpose which
I do not claim as part of my invention I make the upper, carbon holder. E in. one
portion in the form of a rack working in a cylinder F' part of which is cut out
at G to allow pinion H to engage with said rack and so raise or lower carbon
'holder, E.
1
•
At a convenient point on the cylinder or main depending shaft F of the lamp
Isecure a block on which I mount rigidly a bracket or arm projecting, at right
angles to said shaft F and having a short depending arm-Kat or near the end of
which I pivot a rocker or lever L which lies when lamp is in use parallel with or
nearly so and under the bracket or arm J but having opposite end projecting past
the centre shaft F. Near the centre of the rocker or lever. L I mount a rigid
spindle M projecting rearwardly, and carrying a sleeve on which are mounted the
pinion H' and friction wheel O and so arranged that said pinion H shall gear into
racked portion of upper carbon, holder E. at, G., To the opposite end of lever L
I pivot a brake device P in the form of a fork one arm of which P carries a brake P
controlling friction wheel the grip being regulated by a set screw P³ carried
by front, arm P and so arranged that when end of screw. Pa touches; top of
bracket the grip of the brake is relaxed and friction wheel Oturns actuating
pinion H so releasing racked portion of carbon-holder at G and allowing.carbon,
holder E to descend.
The end of lever L is kept nominally up as shewn in Figure 1 by means of a
spring device Q (or its equivalent such as weight) adjusted by set screw: Quor
other well known means. Near the end of lever L Isecure a piece of soft iron. R
forming a core capable of descending into solenoid S, and becoming,the, armature.
offa magnet when current passes through solenoid.
I have now described my improved lamp as constructed after the fashion of a
Brockie Pell or Crompton-Pochiu lamp and being similar in length, but in order
to shorten the holder frame and so make a more compact or smaller lamp I may
dispense with the carbon holder E of rod form and its rack and pinion and pass
the chain from the lower carbon holder over a small pulley or chain wheel which

page_text: would take the place of the pinion H and a guide or idle pulley to give proper
direction to the said chain.
The upper carbon holder would in this case be of similar form to the lower one
and any well known means may be employed for allowing the two holders to
approach each other without interference.
The action of the lamp is as follows. The current entering the coil S (which
is in shunt of the carbons) attracts the oore R which is connected directly with the
lever Land so pulls down the friction wheel O brake P and top carbon holder at
same time raising lower carbon holder and so bringing carbons into contact and
striking the arc.
The spring or weight Q opposes the force of the solenoid and thus separates
the carbons at the moment of the arc being struck by reason of the rocking arm
or lever L with friction wheel and carbon holder E being raised, the said lever L
is now held or balanced between two forces or powers that of the spring or
weight and the attractive force of the solenoid upon its core.
The friction wheel O is at this stage locked or held fast by the brake P.
Upon the are slightly increasing in length greater tension of force is created in
the shunt coil or solenoid S thus attracting the core R and lever L carrying
the brake P and fricition wheel O the free end or set screw P³ of the brake P Dow
comes in contact with or rests upon the top of the bracket or arm J thus slightly.
raising the brake proper P and allowing the friction wheel O to partially revolve
so shortening or bringing the arc to its normal length the spring or weight Q now
slightly predominates and the lever L is proportionately raised the free ond of
brake or set screw P³ being eased' from contact with bracket J so locking or fixing
for the time being the top carbon holder and this action continues as the carbons
burn away.
It must be seen that the action of the brake P2 on the friction wheel O is so
alight and gradual as to be practically imperceptible and that thus there cannot be
any sudden closing or approaching of the carbon points and that the said points
cannot remain in too close proximity as the moment this takes place the tension of
the solenoid is lessened and the free end of the lever L rises so locking the friction
wheel and raising the same together with the carbon.holder.
Having now particularly described and ascertained the nature of my inven-
tion and in what manner the same may be performed 1 declare that what I
claim is :
1. In electric arc lamps mounting or carrying the mechanism for raising or
lowering the carbon holders (or for regulating the distance between the carbon
points) on a rocking arm or lever substantially as hereinbefore described with
reference to the accompanying drawings.
2. The electric arc lamp.constructed and arranged substantially as hereinbefore
described and as illustrated by the accompanying drawings.
Dated this 1st day of March 1895.
POPPLEWELL & Co.,
32, Southampton Buildings, London, W.C., Agents.