Improvements in Electric Arc Lamps.
Year: 1891

page_text: Date of Application, 30th Dec., 1891-Accepted, 19th Mar., 1892
COMPLETE SPECIFICATION.
Improvements in Electric Arc Lamps.
I, GUY CAREY FRICKER, of 15 Spencer Road, Putney, in the County of Surrey,
Electrical 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 :-
This invention relates to a construction of electric are lamp in which the position
of the carbons is controlled by a friction block that is arranged to bear against a
brake wheel connected with one of the carbons and is carried by one arm of a
loaded lever pivoted to a rod connected with or operated by the core in an ordinary
simple or differential solenoid in the lamp circuit, the arrangement being such that
when the length of are falls below the normal, the friction block is moved by the
core and causes the brake wheel to move the carbons apart, and when the length
of arc increases beyond the normal the pressure between the friction block and
brake wheel is lessened and the carbons allowed to move towards each other by
gravity.
And in order that the nature of my invention may be fully understood I will
proceed to explain the same by aid of the accompanying drawings in which
Figs. 1 and 2 are elevations at right angles to each other of an electric arc lamp
constructed according to this invention.
A is a vertical rack working in suitable guides and by which the upper carbon
is carried. B is a holder for carrying the lower carbon. This holder B is con-
nected to the rack A through a rod B³, an insulating stud C, and a chain D that
passes over a pulley E. The rack A gears with a pinion F to the spindle of which
a brake wheel C is fixed. H is a rocking lever pivoted at one extremity I and
operated at the other extremity by the direct vertical movements of the core K of
a solenoid K¹ in the main circuit of the lump. The suddenness of these movements
may be damped by means of a dash pot the piston or plunger of which is worked from
the lever Has for example by the link H¹. L is a bar one end of which is freely
pivoted to the lever H, whilst its other end passes through a fixed guide M so that
may if
a definite direction can be given to its movements as desired. The rod L
desired be carried on a pivot in rigid connection with the solenoid core K, but the
arrangement illustrated is preferred. To the rod L is pivoted a lever N one arm of
which is weighted as at O, whilst its other arm carries a friction block P arranged
to bear against the brake wheel G. Q is an adjustable set screw or stop by which
the weighted arm of the lever N is supported in such a way that the pressure of the
friction block P against the brake wheel G is relieved at a certain position of the
solenoid core K.
This critical position of the core K is that in which, when ordinary well known
arrangements are made in the electric circuit and in the adjustment of the solenoid,
the lamp will work with a normal length of arc any departure from which will be
checked and controlled by the mechanism described.
With the arrangement described, when the core K is sucked upwards above this
normal position as when starting the lamp with the carbons in contact, or when the
arc becomes too short, the fulcrum R of the lever N will be lifted by the rod L and
the block P will be pressed against the periphery of the brake wheel G by the
action of the weighted arm of the lever; the upward movement of the rod L will
thus be transmitted to the periphery of the brake wheel G so as to cause it to partly
rotate and thus through the pinion F and rack A to separate the carbons and strike
the arc if the carbons were in contact, or to lengthen the arc to the normal, if the.
lamp was previously in action. When the core K falls below the said normal
position due to a lengthening of the arc beyond the normal, the fulcrum of the

page_text: lever N will fall and the weighted arm of the lever will be supported by the set
screw or stop Q so that the pressure of the friction block P against the brake
wheel G will be lessened to such an extent that the latter will be able to rotate
under the action of the weight of the rack A which will then descend slightly by
gravity and reduce the arc to its normal length.
A spring may be substituted for the weight O to normally press the block P
against the brake wheel G, the pressure between the two being lessened as before
when the lever comes into contact with the set screw or stop Q.
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed I declare that what I
claim is :-
1. An electric arc lamp in which the position of the carbon is controlled by a
friction block that is arranged to bear against a brake wheel connected with one of
the carbons, and is carried by a loaded lever pivoted to a rod connected with or
operated by the core of a solenoid in the lamp circuit, the arrangement being such
that when the length of arc falls below the normal, the friction block is caused to
partly rotate the brake wheel and move the carbons apart, and when the length of
arc increases beyond the normal the pressure between the friction block and brake
wheel is lessened and the carbons allowed to move towards each other substantially
as herein described.
2. The combination and arrangement of parts constituting my improved electric
arc lamp substantially as herein before described and shewn in the drawings
annexed.
Dated this 20th don
001
W. LLOYD WISE,
Per F. J. Brougham,
46, Lincoln's Inn Fields, London, W.C., Agent for the Applicant.