Year: 1886

page_text: I JAMES SWINBURNE of 34 Holford Square in the County of Middlesex,
Electrician do hereby declare the nature of this invention to be as follows:-
In an arc lamp I arrange the electromagnets so as to act on the arc by mutual
repulsion of cores. The regulating gear consists of an electromagnet with two
cores, of which one can move to or from the other laterally. When magnetised
these cores repel each other, and the repulsion is used to work the lamp. The
shunt circuit is wound so as to weaken this repulsion, or to counteract it. The
moveable core or magnet may be connected directly to the holder or holders without
intermediate multiplying gear.
I prefer to arrange the clutch inside the tubular carbon holder. The tube also
serves as a dash pot, and the plunger of the dash pot, instead of being fixed to the
frame, is connected with the regulating gear, so that the clutch is disengaged, the
carbon holder is still held by the regulating gear. Another plunger may be added
fixed to the frame to steady the motion of the whole.
W
BROOKES & SON,
55 & 56, Chancery Lane, London,
Agents for the said James Swinburne.

page_text: JAMES SWINBURNE of 34 Holford Square in the County of Middlesex,
Electrician do hereby declare the nature of my invention for IMPROVEMENTS IN
ELECTRIC ARC LAMPS and in what manner the same is to be performed, to be
particularly described and ascertained in and by the following statement:-
In an arc lamp I arrange an electromagnet, or electromagnets, so that the lamp
is actuated by their repulsion.
Figure 1 is an isometric projection of the electromagnets of a lamp in diagram
form a is the main or series coil b and c are two soft iron cores When they are
magnetised they have similar poles close together which repel each other. b is
fixed, so crises away from it; and the force with which c presses upwards depends
on the series coil, or main current. d is the shunt coil. It acts similarly except that
the fixed core is here the upper one fand e is the movable core. e and c are con-
nected rigidly together by h, so that the position they take up depends on the
strengths of the main and shunt currents. cand c are connected with the clutches,
so that their movement regulates the arc, gg are the rods of the carbon holders.
The clutches are not shewn in fig. 1. The rods pass loosely through the ends of
the cores serving as guides.
Instead of having the main or series in one coil and the shunt in the other they
may be wound on one coil acting differentially in the usual way. i is a plate of
soft iron to increase the force of the electromagnets.
Fig. 2 is a diagram shewing a form of clutch. a is the coil, supposed to be
wound, say, differentially b and c the cores, of which c moves, is a clutch which
is tilted up so as to bite by the end of the spring k, which is connected to c. The
object of this spring is this. If it were not there, when the clutch slipped, owing
to the end of the lever m touching the flange of the coil a the rod would slip down,
and the clutch would not bite again till c had risen. It takes an appreciable time
for the shunt current to alter and to move c up, so that when the clutch did bite,
the rod would have a considerable momentum, and after some use the rod would
be worn into little nicks. The spring tends to obviate this, for it does not allow
the clutch ever quite to lose its hold, so that the rod slips through gently and very
gradually. This principle may be applied to many of the forms of clutch in
common use. I prefer to put the clutch inside the carbon rods g g. This is shown
in diagrammatic form in Fig. 3. g is the rod, or tube filled with glycerine. n is
connected with the magnet core c and through the spring t to the clutch which
is shewn diagrammatically as a short lever which jams when held at one end, but
lets the outer tube slip when the other end is tilted up. p is a dash pot piston
connected to the rod n and s is a dash pot piston connected to the rod o which is
connected to the frame work of the lamp. As t falls and g with it, one end of q
comes in contact with the stop r which tilts it and lets the tube slip, feeding the
arc till t is raised and q grips again p prevents the magnets moving quickly
relatively to g, and 8 prevents either moving quickly relatively to the frame of the
lamp. It is not necessary to use both the spring t and the double dash pot.
To make one carbon feed before the other carbon, one clutch is set to slip before
the other. The weight of the cores and rods is partly counterbalanced by springs.

page_text: When carbon is burned there is less weight so the lamp tends to burn with a
longer arc. This is counterbalanced by insulating the rods g g from the frame,
and arranging that the main current through the first carbon has to pass through a
few extra coils on a.
Having now particularly described and ascertained the nature of my said
Invention, and in what manner the same is to be performed, I declare that what
I claim is
1. The construction or arrangement and use of parts of arc lamps so that the
feed is regulated by the mutual repulsion of similar poles of electromagnets sub-
stantially as set forth.
2. The construction or arrangements and use in an arc lamp of a clutch or
clutches supported by a spring or springs substantially as and for the purposes set.
forth.
3. The combination with or arrangement in an arc lamp of a double dash pot
substantially as described and for the purposes set forth.
4. The method of or arrangement of parts for electrically counterbalancing the
loss of weight due to combustion of carbon as set forth.
Dated this 16th day of September 1886.
WM BROOKES & SON,
55 & 56, Chancery Lane, London,
Agents for the said James Swinburne.