Year: 1886

page_text: Date of Application, 9th June, 1886.
Specification Accepted, 7th Jan., 1887.
I HERMANN MOEHRING, Engineer, residing at the City of Frankfort on the Main
in the Empire of Germany 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 :-
Nearly all the arc lamps hitherto constructed may be divided into two clases; In
one of these the distance between the carbons or the length of the arc is regulated
by the action of solenoids or helices on their cores, the latter being directly connected
to the carbons without any intervening disengaging clutches or clamps. In the other
class the gravity of the upper carbon and its carbon-holder and rod is employed to
cause the carbon, when a clamp or clutch attaching it or its rod to a magnet is dis-
engaged or released to slide down either freely or more or less controlled by clock-
work the carbon being separated or the upper carbon raised, by the clamp or clutch
again grasping the rod and drawing it upwards. The first of these two classes has
the serious defect that the regulation of the carbons is too sensitive to variations of
the electrical current and therefore in order to insure steadiness of the light, requires
to have considerable resistances either added to cach lamp, or as internal resistance
of the actuating dynamo machine, or both. The second class mentioned, has the great
defect that the mechanism is unreliable and likely to fail when even minute quantities
of dust or dirt settle on the rod, clock-work or other parts.
These defects are avoided in my lamp, the carbons being forced
by a comparatively great power in a uniform and steady manner.
Figures 1, 2 and 3 show my improvements in diagram form.
as actually built in reduced size or scale.
together or apart,
Figure 4 shows it
In Figures 1, 1, and 2 a scale beam, consisting of two sides a a', connected at their
ends by the transverse pieces cel and turning easily on the pivots bb is shown. The
transverse pieces c c are bent to a proper form as shown, and form armatures for the
electro magnets d d to act upon. The helix of d is of thick wire and gives passage
to the main current of electricity whilst the helix of d is of thin wire and gives passage
to a shunt current. The scale beam side has a short arm projecting downwards
from below its centre which arm is furnished with a sliding contact piece g and also
on each side of g with two pieces h h of non-conducting material. When the scale

page_text: beam stands in a horizontal position a spring forms contact with which contact is
broken as soon as the scale beam inclines to either side. F is a horse-shoe electro-
magnet, its armature suspended on the springs in such a position that when a
current passes through the helices of the magnet the armature k is drawn upwards,
and when no current is passing, it is drawn downwards by the springs. To the
lower end of a sliding contact piece is attached, which is in contact with a plate
when the armature k is down, and with when k is drawn upward. The up and
down movement of the armature is transmitted by means of the pawls n n' to the
ratchet wheel o in the following manner. When the scale beam is inclined towards
the slide of magnet d a portion of its short middle arm throws the pawl n' out of gear,
and the up and down movement or vibration of will manifestly cause the wheel o to
be rotated in the direction from left to right; when on the contrary the scale beam is
inclined towards magnet d¹, pawl will be thrown out of gear and consequently the
up and down movement of will cause wheel to be rotated from right to left.
On the same shaft which carries o, a worm is fastened working in the worin wheel u
and attached to the same shaft as the latter are two wheels around which cords or small
wire cables are wound, one in a different direction from the other. One of these cords
or cables is attached to the upper carbon, and one to the lower carbon by means of
holders or clamps. The wheel around which the cord of the upper carbon is wound is
double the diameter of the one around which the cord of the lower carbon passes, so
that the movement communicated to the upper carbon by its wheel is double that of
the lower carbon. A is a short circuit magnet, such as is now employed in most
lamps.
A pawle attached to a spring works into the periphery of wheel.
This pawl
permits the wheel to turn freely in the direction which corresponds to draw the
carbons together, but on the contrary it limits the extent to which the carbons can
be separated each time when the carbons are drawn apart, the spring becoming
compressed until a collar on the pawl prevents further motion downwards.
The operation of the mechanism of my improved lamp is as follows:—
Suppose the carbons are separated from one another and no electric current passing
to the lamp. In consequence of the scale beam being weighted heavier at the end c¹
it will be inclined in that direction and spring will rest on the insulated piece ².
The
The armature will rest on set screw the spring pon, the pawl will be in
gear with wheel o the pawl a being out of gear and finally the armature t of the short
circuit magnet A will rest on the set screw s forming contact therewith. Suppose
then that the proper electric current is sent to the lamp to operate the same.
current will enter at the positive pole Z, pass by the shunt circuit a, y through the
helices of the magnet F and thence through r, 2, 1, A, t, and s to the negative pole Z.
The magnet will at once draw its armature upward and the contact between p
and 7
Being broken the current will not pass any more through the helices of
magnet F but take the direct way of least resistance through 7, 1, A, t, s, to Z. But
armature being no more held upward in consequence of the magnet F having lost
its current will be carried downward by the springs until the motion is arrested
by y, and contact again formed between and contact between pand being
ruptured. Of course the current will then take the first mentioned direction and
with the same result and again and again the armature will rise and fall in rapid
succession.
This vibration of acting on the pawl ' and thence by means of wheel o, and the
worm wheel on the wheels carrying the connecting cords or cables to the carbons will
draw them together until they are in contact. A portion of the current will then
pass through the helix of magnet A and thence through the helix of magnet d to
the negative pole Z and in consequence both magnets will attract their armatures the
main current then taking the way Z,, y, p, k, l, B, thence through the carbons,
and further through w and d to Z. The armature e having been attracted by magnet d
the scale beam is now inclined towards that side and in consequence spring will rest
on the insulated piece h, pawl a will be in gear and pawl n² out of gear with o and the
vibrating motion of k will turn wheel o in the contrary direction from that described

page_text: The
above, thus drawing the carbons apart and forming the electric are the length of
which is limited by the action of pawl e as already described. By the separation of
the carbons the resistance to the current passing through them is increased, and a part
of the current is shunted through the helix of magnet d' which as mentioned above is
of much thinner wire, offering greater resistance than the helix of magnet d.
relative resistances of the helices d and d¹ are made so that when the carbons are
separated so as to form the desired length of arc, the attraction they exert on their
arimatures is equal and in consequence the scale beam assumes a horizontal position.
But in this position is in contact with g, which being a part of the scale beam
and the latter being electrically connected to through the frame of the mechanism,
the current will take the shortest route Z, f, g, ", B, through the carbons we and d
to 7. The magnet F receiving no current ceases to act, its armature ceases to vibrate
and the whole mechanism is at rest. This condition of rest remains until, in conse-
quence of the carbons consuming, and the are becoming longer, a greater resistance
is offered to the passage of the current. This causes more current to pass through
the helix of d rendering its attraction greater than the attraction of d, and in conse-
quence causing the scale-beam to incline towards d. The magnet F receives
current again and commences to operate, and as pawl al is in gear and n out of gear,
as at first described, the carbons are gradually and surely drawn towards one another
until, the proper distance or length of are being established, the scale-beam returns to
its horizontal position and in consequence the mechanism is again brought to rest.
I can substitute for one of the magnets d d a weight or spring, but I prefer using
two as described.
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 employment in electric arc lamps of armatures bent so as to partially
surround the poles of electro-magnets substantially as and for the purpose described.
2. The employment in electric are lamps of a scale-beam furnished with armatures
at its ends acted upon by electro-magnets, or furnished at one end with such an
armature and at the other end acted upon by weights or springs, the said scale-beam
acting by changing its position, to put the mechanism for regulating the distance
apart of the carbons or length of are in and out of motion, substantially as and for the
purpose described.
3. The combination in electric are lamps of an electro-magnet F with a scale beam
whose change of position gives or shuts off the current to said electro magnet and
throws in and out of gear pawls attached to the vibrating armature of the same this
causing the ratchet wheel into which the pawls work to rotate in one direction or the
other, and causing the carbons to approach one another or separate substantially as
described.
4. The employment in electric are lamps of a pawle attached to a spring and
furnished with a collar or an equivalent thereto, for limiting its motion or play, the
said pawl thus limiting the amount to which the ratchet wheel into which it works,
can rotate in the direction corresponding to a separation of the carbons, whilst it
leaves unlimited the amount of rotation of its ratchet wheel in the direction corres-
ponding to the carbons approaching one another.
AA MOEHRING.
By Harris & Mills,
23, Southampton Buildings,
Agents.