FOR ELECTRIC MACHINES
Year: 1882

page_text: PROVISIONAL SPECIFICATION left by the said William Fisher at the Office
of the Commissioners of Patents on the 12th April 1882.
WILLIAM FISHER of Birmingham in the County of Warwick
CURRENT DIRECTOR FOR ELECTRIC MACHINES"
"AN AUTOMATIC
My invention has for its object an improved device which I call "an automatic
current director for electric machines which is specially applicable to the
machines used for the deposition of metals such as plating and electrotyping. Tho
device is for the purpose of preventing the current passing in the wrong direction
which sometimes takes place as the machines are now used.
My invention consists in a permanent magnet suspended between two electro
magnets in such a manner that it is attracted by one or the other according as the
current passes one way or the other through the coils of the electro magnets. The
permanent magnet throws into circuit one of two other electro magnets the
armature of which carries with it the connections in such a manner that tho
current must always pass in the same direction through the external conductors.
The magnets between which the permanent one is suspended may be made of
round iron say three eighths of an inch in diameter and coiled with about twenty
turns of insulated wire. The current passing round these magnets must be
adjusted by a resistance so that they may be equal in attractive power to the
permanent one.
The other pair of magnets may be made of round iron say three quarters of an
inch in diameter and may be coiled with four laps of say sixteen guage insulated
copper wire. The armature of these magnets is of soft iron and is jointed below
the magnets in order that its weight may be used to break contact after it has
come over. A shunt current is sufficient to hold down the connections if that be
preferred to a weight.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said William Fisher in the Great Seal Patent Office on the 12th October
1882.
WILLIAM FISHER of Birmingham in the County of Warwick
CURRENT DIRECTOR FOR ELECTRIC MACHINES"
"AN AUTOMATIC
My invention has for its object an improved device which I call an automatic
current director for electric machines which is specially applicable to the machines
used for the deposition of metals such as plating and electrotyping. The device is
for the purpose of preventing the current passing in the wrong direction which
sometimes takes place as the machines are now used.
My invention consists in a permanent magnet suspended between two electro
magnets in such a manner that it is attracted by one or the other according as the
current passes one way or the other through the coils of the electro magnets. The
permanent magnet throws into circuit one of two other electro magnets the
armature of which carries with it the connections in such a manner that the
current must always pass in the same direction through the external conductors.
The magnets between which the permanent one is auspended may be made of
round iron say three eights of an inch in diameter and coiled with about twenty
turns of insulated wire. The current passing round these magnets must be
adjusted by a resistance so that they may be equal in attractive power to the
permanent one.
The other pair of magnets may be three quarters of an inch in diameter and
may be coiled with four laps of say sixteen gauge insulated copper wire. The
armature of the magnets is of soft iron and is jointed below the magnets in order
that its weight may be used to break contact after it has come over. A shunt
current is sufficient to hold down the connections if that be preferred to a weight.
The accompanying drawings will serve to make ny invention more readily
understood.
Figures 1 and 2 are a plan of one modification of my machine mounted on any
suitablo base plate R, R.
Figure 3 is an olevation of Figure 1 and Figure 4 is an elevation of Figure
and Figuro 5 is an inverted plan under the base plato R, R showing the con-
nections in this particular modification, but the connections may of course bec
considerably varied with the same practical effect.
The machine illustrated consists of two parts-First the permanent magnet A
suspended between the electro inagnets B and C. The magnet A is suspended
between the two pillars and y Figure 2.
Second the electro magnets E and F between which the armature D works.
The armature D has at each end a rocking piece H and I which are jointed to it.
These rocking pieces are connected to the machine at the terminals J and K shown
on the plan of the connections Figure 5. The rocking pieces H and I must be
capable of being connected with either M or N see elevation of Figure 1 vis
Figure 3 according as the magnets E or F is in circuit. M, M, M and N, N, N on
the plan of the connections are connected to the vats by the terminals M' and N'.
The action in this modification is as follows:-When the permanent magnet A
is attracted by B or C it comes in contact with the piece Z or Z' according as it is
attracted by one or the other. This contact completes the circuit round the
Inngnets or F. At O and P there is a connection which the armature D breaks

page_text: in its passage over from one side to the other, so that the current round the
magnets E and F is only momentary. In regard to the plan of connections
Figure 5 it is intended to show that the piece M¹, M, M and 'N', N, N are crossed
in order to make the pieces N, N Figure 1 practically one piece and M, M in the
same Figure also one piece. Where the fine lines representing the wire passing
round the electro magnets show a break they pass through the base R of the
machine and round the magnet then back again in order to cross. This arrange-
ment is however simply for neatness in construction and not essential to the
working and about which I make no claim.
The ends marked K, N¹, J, M' are the terminals, J. and K being connected to a
"given machine" the current of which it is necessary to direct. M' and N¹ are
connected to any arrangement through which it is required to pass a continuous
current in one direction: Suppose first that the current from the machine enters
my director at J the director will automatically take up a position such that the
suspended magnet A will be attracted to the magnet B making contact with the
pieces Z¹ throwing the magnet E into circuit and bringing the pieces H and N
Figure 3 and I and M into contact. The current will then pass from J towards H
and so on to M then through M' to its destination returning to the director at N¹
then on to N so to I so on to K then back to the machine. The special point to
be noticed is that the current leaves the director at M' and returns at N'. Supposo
now the current froin the "given machine" to reverse i.e to enter my director
at K instead of J the suspended magnet A will at once move to the magnet C
throwing into circuit the magnet F changing the contact of H from N to M and
that of I from M to N. The direction of the current will therefore be from K on
to I so on to N on to N¹ where it leaves the director, for its destination as before
returning to M' on to H so to J where it returns to the machine.
Further referring to the diagram sketch Figuro 6 the action will be as follows:
If the current be supposed to pass in the direction of the arrows and the poles to
be as marked the permanent magnet A will be attracted to the electro magnet
marked C the electro magnet B repelling and so assisting its movement. When
however there is a change of direction in the current the polarity of the electio
magnets is changed the s poles taking the place of the n poles and the reverse.
The permanent magnet will then be attracted to the electro magnet marked B and
repelled by the electro magnet C-The permanent magnet A will therefore move
to the magnet marked B.
It will be at once evident to those conversant with the subject that various
modifications of the arrangment illustrated may be carried out for the attainment
of the same desired end without departing from the principle of my invention the
object being by a combination of electro and permanent magnets to ensure a
movement of one of the magnets upon any change of polarity which takes place
immediately the direction of the electric current is changed in a given electric
machine to which my director may be attached-I will explain three of such
modifications:-
:-
First: The movement of the centre magnet will be secured if it be an electro
magnet and the stationry magnets are both permanent ones as per diagram sketch
Figure 7. In this case the polarity of the central magnet will change causing the
attraction and repulsion as before.
Second-Referring to diagram Figure 8 and supposing the current to enter in
the direction of the arrow and the poles to be as marked there will be attraction
and the pieces will come together. When the direction of the current changes the
poles will change in the electro magnet and repulsion will take place the pieces
separating.
Third: Practically the same thing will occur if the magnets are changed as per
diagram Figure 9.
Having now described my said invention and the manner of carrying the same

page_text: into practice with some of the modifications in carrying the same into effect, I
would have it understood that what I claim as my invention is:-
The arrangement of a suspended or moving magnet in combination with a
stationary magnet or magnets which will be operated by a change of current as
and for the object herein set forth.
In Witness whereof I the said William Fisher have hereunto set my hand
and seal this tenth day of October in the year of our Lord One thousand
eight hundred and eighty two.
WILLIAM FISHER (L.B.)