Improvements in Electric Switches.
Year: 1896

page_text: Date of Application, 21st Apr., 1898-Accepted, 23rd May, 1896
COMPLETE SPECIFICATION.
Improvements in Electric Switches.
We, ELMER HOWARD WRIGHT, of No. 6650 St. Lawrence Avenue, Chicago,
Illinois, Electrician, JAMES JEAN HECKMAN of No. 9 St. James Place in said
Chicago, Attorney, ALBERT HENRY GRAVES, Attorney of No. 931 Victoria
Avenue, in said Chicago, CHARLES CALVIN CARNALAN of Downeri Grove,
Illinois, Attorney, and WILLIAM HENRY CARNAHAN, Millor, of Apollo,
Pennsylvania, 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 improvements in electric switches and more specifically
to an improved multiple contact switch especially adapted for simultaneously
effecting a change of polarity or circuit in a plurality of conductors connected with
or controlled by said switch.
We are aware that it is not now to provide a switch having a plurality of circuit
controlling contacts operating to simultaneously change or shunt one or more
circuits to different lines, or a switch adapted to simultaneously reverse the
polarity of a plurality of lines, but neither of these constitutes our invention. A
principal object of our invention consists in providing a switch adapted to control
a plurality of circuits (at least three) of different character or potential, and by
means of which their relation to one another may be changed at pleasure.
The object of the invention is to provide a simple and efficient device of the
character referred to, and the invention consists in the matters hereinafter
described and more particularly pointed out in the appended claims. The invention
will be readily understood from the following description, reference being had to
the accompanying drawings in which :-
Figure 1. is a perspective view of a switch embodying our invention.
Figure 2. is a detail of one of the pairs of contact tongnes.
Figure 3. is a perspective view of a switch board provided with six fixed contact
points.
Figure 4. is an enlarged detail in perspective of an end portion of the contact
carrying bar shown in Figure 3, inverted.
The invention is herein shown as applied to the Edison three wire system of
incandescent electric lighting; a switch embodying our invention being specially
adapted for readily accomplishing the changes of circuit with relation to each other
necessary to secure proper polarity in the conductors, as will hereinafter more fully
appear, but it is to be understood, that the use of the switch is not limited to this
particular purpose, the invention obviously being capable of use in various other
ways, and either in its present embodiment or in other forms adapted to the
particular use to which it is applied.
In the Edison three-wire system the triple arrangement of couductors extends
throughout the entire system, each branch comprising a positive, negative and
neutral conductor. In practice the main distributing branches or under-ground
leads are laid in metal pipes; the three insulated wires being packed together and
inserted into a pipe only large enough to receive them. The interstices between
the conductors and pipes are usually filled with a solid composition of insulating
material.
In wiring for this system of lighting it is the uniform practice, and one of the
requirements of the Board of Underwriters, that a switch or cut out (technically

page_text: called the "service cut out ") be provided immediately adjacent to where the
secondary branch enters each individual building, so that when necessary the circuit
in the entire building nay be instantly cut out. From this switch or cut out the
secondary branch leads to the various floors and points in the building from which
it is desired to distribute to the individual lamps, each of these latter distributing
points being provided with a "branch cut out."
Notwithstanding the care taken in the preparation and laying of the conductors
forming the main leads, owing to the powerful current which they carry, the
insulation is frequently destroyed and the current "grounded." When this happens
the current usually burns and melts both the pipe and the conductors therein so
that the ends of the conductors or leads will be separated by a considerable space
which must be filled in with new conductors.
Upon the discovery of a break the lineman first proceeds to the building where
the lights have failed and tests at the "service cut out." If no current comes to
the building it is certain that the trouble is in one of the main or street leads, and
be thereupon throws out or opens all of the "service cut out" switches of the
building affected by the break. Having done this he proceeds to locate the break
and repair the same.
Owing to the manner in which the conductors are insulated and embedded within
the piping, and the fusing and shortening of the ends of the leads, as horeinbefore
described, it is usually impossible to determine certainly which is the neutral and
which the positive and negative leads of the "dead" end of the branch, and even
were it possible or practicable to determine how the ends should be properly
connected, it would in many instances be extremely difficult or inconvenient to do
so owing to the difficulty of manipulating the wires thus covered. For this reason
it is the general practice of lino repairers to pay no attention whatever to the
identity of the lends but to simply connect the ends in whatever way is most
convenient. The chances are, therefore, two out of three, that the conductors will
bo connected in such a mauner as to change or cross the circuits.
The line having been repaired the liueman proceeds to the service cut out, tests
the live ends of the conductors or those leading to the street main, thus determining
which is the neutral and which the positive and negative, and if he finds that the
conductors have been crossed by their relative polarities changed by the repairing
of the break be thereupon proceeds to disconnect the conductors and rearranges
them in their proper relation. This is a work of considerable difficulty owing to
the relatively large size of the conductors and the difficulty of manipulating them,
and more especially so because it must usually be performed in inconvenient
locations; usually in the basement of the building closely adjacent to the outor
wall thereof, and in many instances in some inconvenient recess or angle where the
conductors will be least in the way. It will be obvious, furthermore, that this
work of testing, disconnecting and rearranging the conductors must be performed
at each service cut out affected by the break, and with an easy possibility of making
a wrong connection notwithstanding the tests made. It is absolutely necessary
that these connections be correctly made, before tho current is turned on, because
if otherwise connected the effect is to increase the voltage on the lamps on one side
of the neutral to such an extent as when thrown into circuit to instantly disable,
and in many instances completely destroy every lamp on that side.
It is the object of the present invention to provide a switch by means of which
the proper relations of the circuit conductors may be readily and certainly
established; the particular device herein shown being designed to be used in lieu
of the "service cut out."
Referring now to Figure 1. in which is illustrated a switch embodying our
invention, I designates the base or support of insulating material, usually of slate or
linrd rubber, upon which is mounted a plurality of contact points, for the present
use of the switch, seven in number as K, K', K', K, K, K, K. In the present
instance the switch is constructed with what are commonly known as "knife
contacts. That is to say, each of the contact points comprises a blade or male
"

page_text: member, adapted to enter between two resilient tongues comprising the femalo
member of the contact points. The blades K, K, etc., are arranged to stand at
uniform intervals apart in parallel vertical planes, in a row or series across one end
of the base I; being to this end secured upon or made integral with metallic baso
portions suitably mounted upon the base I. The contact points K, K³,
and K, K, are electrically connected in pairs, as herein shown, by means of
metallic base portions kk, while the two outer contact points K and K', are
electrically connected with each other and with the central blade K by means
of a conductor . L, L', and L, are three binding plates, provided at each end
with binding screws 1, 1, mounted upon the base 1, and electrically connected with
the base portion of the contacts K', K, and K respectively. In the present
instance these connections 1, 1, P, are in the form of fusible strips, for the purpose
of protecting the lamps from any sudilen excess of current.
M, M, and M2, are three pairs of spring contact tongues adapted to fit upon and
embrace the contact blades of the switch. These contact tongues are secured in a
vertically depending position upon a suitable insulating bar N at a distanco apart
exactly equal to twice that of the intervals botween the bla les K, K', etc., so that
when in contact, the spring tongues will engage alternate ones of the said blades.
From cach pair of tongues M, M, M', extends a flexible conductor 0, 0, 0,
respectively, having connection at their opposite ends with suitable terminals or
binding studs P, P, aud P. Preferably, and as herein shown, these flexible
conductors will be connected with the tongues and binding studs by soldering,
thereby forming a perfect metallic union, and may conveniently be constructed of
ordinary insulated conducting wire. It will be noted that each of the flexible
conductors is somewhat longer than is necessary for it to reach between the tongues
and binding studs when the former are in their central position, us herein shown;
such extra length being provided in order that the switch bar may be shifted
laterally in either direction and placed in contact with the alternate blades K³, K,
and K, or K, K, and K'; or reversed by turning the bar around in a horizontal
plane end for end and placing it in contact in the central position or shifted to either
side, as before described. Each of the binding studs is provided with a binding
Fcrew, as p, p, p, by means of which the conductors leading from the street
leads may be counected with the switch. For convenience of manipulation, the
bar N is provided upon its upper side with a suitable knob or handle N', by means
of which the switch bar may be lifted up aud replaced as desired. Preferably a
pair of insulated rests of blades Q, Q, will be provided upon the base I, upon
which the tongues M, M2, may be placed when it is desired to leave the switch
open.
The use of the switch thus described is as follows: Normally or when the
currents are not crossed the movable member of the switch will be arranged in
contact with the central contact blades, that is to say, the central pair of spring
contact tongues will be in contact with the central blade K, while the outer pairs
of tongues will rest in engagement with the blades K', and K, respectively. In
this position of the switch the circuits will be in direct lines across the switch-
board; should a break in the main lead occur, the lineman will throw the local
system of the building out of circuit while the break is being repaired, by simply
with-drawing the movable member from the contact blades and placing it upon the
insulated rests. After the break has been repaired and the curront turned on, the
lineman will proceed to the switch, and applying his instrument to the tongues of
the movable men.ber determine whether or not the wires have been crossed in
repairing the break. If he finds that one of the onter conductors, as for instance O,
has become the neutral line, he will, in closing or replacing the switch bar shift
it from its normal central position to that side of the switch-board on which the
neutral line is found to exist. That is to say, if he finds that the conductor O, hus
become the neutral line, he will place the bar in such position that the tongues M
will be in engagement or contact with the blade K, the tongues M', with the
blade K, and the tongues M', with the blade K. If now the circuit be traced it

page_text: will be seen that the neutral line O leads from binding stud P, to tongue M, thence
through the blade K, conductor 2, and to lamp circuit through plate L'; no other
exit or circuit existing, and the neutral being therefore transposed to its proper
central relation.
Similarly, assuming O', to have become the positive conductor, the current will
pass through the tongues M', blade K, from thence through the base, to
blade K', and out to lamps through plate L. The circuit in negative O will be
transmitted across the board precisely similar to that of O'.
On the other hand, should the test disclose that O' has become the neutral, then
the lineman will shift the switch to thet sido of the board with the same result
of properly transmitting the several circuits across to the lamps.
If, however, it be found that the neutral lias been properly connected and remains
central but the negative and positive lines have been transposed, the operator
will reverse the bar by turning it end for end and replacing it, and similarly
if the neutral has been changed to either side and the other two transposed,
the bar in its reversed position may be shifted to one side or the other, as
required.
It
The foregoing is a description of what we consider a preferred form of embodying
our invention and a sufficient illustration for a full comprehension of the same.
is to be noted, however, that various modifications may be made, without departure
from the invention and without the exercise of more than ordinary mechanical
skill. It will be obvious, for instance, that a switch-board having but six contact
points as shown in Figure 3 may be constructed which will serve to transpose the
neutral line to the center in the same manner as in the former construction.
In said figure J' designates the base, R R R R R and R' the fixed contact
studs, four of which are mounted upon three parallel embedded bars T T T
each provided at its end with a binding screw it, respectively. Each of the
two contact studs R R* not mounted upon one of the embedded bars is electrically
connected with one of those that is, the stud R with R and R with R', by
menus of conductors embedded in the under side of the base, as indicated in dotted
lines. S' designates the contact carrying bar, the tubular bifurcated
contacts thereof and the three flexible conductors extending from the
respective contacts to binding studs U U' U*.
It is also clear that the flexible connections may be of various forms; or pivoted,
sliding or other forms of connections may be employed in combination with bars
or other flexible conductors. It will be obvious, furthermore, that the device may
be placed in line at any desired point, other than in lieu of the "service cut out.
These and other analogous modifications we claim as being within the scope of our
inventions.
Having now particularly described and ascertained the nature of our said inven-
tion, and in what manner the same is to be performed, we declare that what we
claim is-
1. A three-wiro system switch comprising a switch-board provided with two sets
of terminals, each of which sets of terminals embraces three binding screws or
connecting devices, a plurality of contact points on said switch-board, arranged
in three electrically connected groups, each of which groups is electrically
connected with one of the terminals of one of the said sets, and a movable
member provided with a plurality of contact points each electrically connected
with one of the terminals of the other set of the switch-board, the contact
points of the movable member being adapted for various engagement with those
of the switch-board, substantially as set forth.
2. A three-wire system switch, comprising a switch-board provided with two
sets of terminals, each of which sets embraces three binding screws or connecting
devices, a movable member, contact points thereon, each electrically connected
with one of the terminals of one set by meaus of a flexible conductor and a
number of contact points on the switch-board in excess of those on said movable

page_text: member, arranged in three electrically connected groups, each of which groups is
electrically connected with one of the terminals of the second set, the contact
points of the movable member being adapted for various contact with the contact.
points of the switch-board, substantially as set forth.
3. A plurality contact permutation switch, comprising two sets of terminals, each
of which sets embraces a terminal for each line conductor of a system composed of
an odd number of line conductors, two contact carrying members one of which is
movable with relation to the other, one of said members being provided with a
contact point for ench line conductor and the other member being provided with a
number of contact points in excess of the number of line conductors, arranged in
electrically connected groups equal in number to the number of line conductora
each group electrically connected with one of the terminals of one set, and each
contact point of the other member being electrically connected with one of the-
terminals of the other set, the contact points on one member being alapted for
various contact with those of the other member, whereby the relations of currents
of different characters carried by said line conductors may be changel at will,
substantially as set forth.
4. A three-wire system switch comprising a switch-board provided with two sots
of terminals of three each, a plurality of contact points arranged upon said switch-
board in three electrically connected groups, each of which groups is connected
with one of the terminals of one set, a contact carrying nembor provided with
three contact points adapted for various engagement with those of the switch-
board and flexible conductors connecting each of the contact points of the
movable member with one of the terminals of the second set, substantially as sut
forth.
5. A three wire system switch comprising a switch-board provided with two sets.
of terminals of three each, seven contact points, arranged in a series at uniform
intervals apart across said switch-board and electrically connected in three groups,
each group electrically connected with one of the terminals of onu set, one of said
groups comprising three contact points and the other groups two each, and a
contact carrying switch bar provided with three contact points spaced at a distance
apart equal to twice the distance between those of the awitch-board and adapted
for various engagement with the latter; said contact points of the switch bar each
having electrical counection with one of the terminals of the second set by means
of flexible conductors, substantially as set forth.
6. A three wire system switch comprising a switch-board provided with two sets
of terminals of three each, seven contact points arranged in a series at uniform
intervals apart acrusa said switch-board and electrically connected in three groups,
each group electrically connected with one of the terminals of oue set, one of said
groups comprising three contact points and the other groups two each, and a
contact carrying switch bar provided with three contact points spaced at distances
apart equal to twice the distance between those of the switch board and adapted
for various engagement with the latter; said contact points of the switch bar each
having electrical connections with one of the terminals of the second set, by means
of flexible conductors and fusible strips interposed in each circuit between the
terminals of the switch substantially as set forth.
7. A plurality contact permutation switch comprising two sets of terminals, oach
of which sots comprises a terminal for each line conductor of a systema compused
of an odd number of line conductors, two sets of contacts, one of which sets
comprises a contact for cach line conductor, each connected with one of the
terminals of one set, and the other of which sets of contacts comprises a number
of contacts in excess of the number of line conductors, said last mentioned contacts.
being electrically connected in a number of groups equal to the number of line
conductors, each of which groups is electrically connected with one of the
terminals of the other set, and means for bringing the contacts of ono set into
various electrical connections with those of the other, substantially as set forth.

page_text: In testimony that we claim the foregoing as our invention, we affix our signatures
in the presence of two witnesses.
Dated this 1st day of April 1896.