Systems for Controlling Electric Lights.
Year: 1894

page_text: Date of Application, 3rd Apr., 1894-Accepted, 19th May, 1894
COMPLETE SPECIFICATION.
Systems for Controlling Electric Lights.
I, CHARLES ARTHUR ALLISON, of 52 Chancery Lane, London, in the
County of Middlesex, Patent Agent, do hereby declare the nature of this invention
(which has been communicated to me from abroad by The Electrical Specialty
Company, Incorporated, of 27 Sheridan Building, in the City of Denver, County
of Arapahoe, State of Colorado, United States of America), and in what manner
the same is to be performed, to be particularly described and ascertained in and by
the following statement :-
My invention relates to an improved system for controlling the electric current,
and has for its special object, the controlling of lamps from any number of points
in an incandescent circuit. The invention consists of the features hereinafter
described and claimed all of which will be fully understood by reference to the
accompanying drawing in which is illustrated an embodiment thereof.
In this drawing,
Figs. 1 and 2 illustrate suitable switch mechanism for use in my improved
system.
Fig. 3 is a perspective view of one of the contact plates employed.
Fig. 4 is a section taken through the line x-x, Fig. 1.
Fig. 5 is a section taken through the line y-y, Fig. 2.
Fig. 6 is a diagrammatic view illustrating the circuit.
Figs. 7, 8, 9 and 10 are similar views, further illustrating the circuit.
Similar reference characters indicating corresponding parts or elements in these
views, let the numeral 5 designate the switch base plate employed in the
construction shown in Figs. 1 and 2. This base is preferably composed of
insulating material and is provided with a post upon which is pivoted a toothed
insulating block or ratchet disk 12. In the construction shown in Fig. 1, a contact
plate 7 of the design shown in Fig. 3 is attached to one face of the disk. This
plate is provided with lips 7 which overlap every alternate tooth of the ratchet.
To the base 5 of the switch are attached the three contact brushes 8, 9 and 10.
The brush engages the face of the disk covered by the contact plate 7 and is
therefore always in contact therewith. The brushes 9 and 10 engage the edge of
the disk, being so arranged that when one engages a contact lip 7 the other
engages an exposed tooth 12ª of the insulating ratchet. In the construction shown
in Fig. 2, a contact plate 7 is applied to each face of the disk 12, whereby every
tooth of the ratchet is provided with a contact lip 7ª. This switch has four
brushes attached to the base 5 and designated 13, 14, 15 and 16 respectively.
It may therefore, be called a four wire switch. The brushes 13 and 16 engage the
contact plates 7 on opposite faces of the disk, each being continuously in engagement
with its respective plate 7. The brushes 14 and 15 engage the edge of the disk
and each is always in engagement with a contact lip of one or the other of the
plates, and alternately in contact with the lips of the two plates as the disk is
rotated by the use of the push har 17 carrying the dog 18. This mechanism for
actuating the ratchet is given the reverse movement by the spring 19. In Fig. 6,
let A, for convenience, designate switches of the construction shown in Fig. 1,
and B, switches of the construction shown in Fig. 2. In my improved system, two
switches A are located at suitable points in the circuit, and the switches B
intermediately located. Between the switches A and B, the circuit wires are
double. As many switches B are interposed in this double portion of the circuit as

page_text: desired, and the number required will depend upon the number of points between
the terminal switches A from which it is desired to control the lamps in the
circuit.
By the use of the duplex or three wire switches A, it is well known that lamps
can only be controlled from two points in the circuit. By running two wires
between these two points, where the duplex switches are located, and interposing
the switches B in this double part of the circuit, the lamp may be controlled from
as many additional points as there are switches B.
This proposition will be understood by a careful inspection of the diagram
shown in Fig. 6, bearing in mind the construction of switches A and B. Only two
switches B are shown in this fig. (it must be remembered, however, that any
desired number may be employed), two being considered sufficient to illustrate the
principle or make the system clear. Let the numeral 20 designate the lamp or
series of lamps which it is desired to control, and 21 and 22 the two wires between
the two switches A. Assuming that the switches A are in the position shown
in Fig. 1, and that switches B are in the position shown in Fig. 2, the current may
be said to pass from the conductor 23 of the main circuit to the lamp and thence
through wire 24 to brush 8 of one switch A and thence across the face plate to
brush 10 of the same switch, thence through wire 21 to brush 15 of one switch B,
thence across the face plate to brush 13 of the same switch, thence ria wire 22 to
brush 14 of the other switch B, thence across the face plate to brush 16 of the
same switch, thence via wire 21 to brush 10 of the other switch A, thence across
the face plate to brush 8 of the same switch and thence to the main circuit wire 23,
the circuit being closed and the lamp lighted. Now if the ratchet of either of the
switches A, or of either of the switches B is actuated or moved one notch, which
can be done by pressing the push bar, the circuit will be broken and the lamp
extinguished. Assuming that the ratchet of the switch B farther to the right
in Fig. 6 is thus actuated, the current must follow the course shown in Fig. 7 and
pass from wire 21 on one side of the switch to brush 15 and thence across the face
plate to brush 16 and wire 21 on the opposite side of the switch, and finally
to brush 9 of the switch A farther to the left, the circuit being broken since there
is no electrical connection between brushes 8 and 9 as will be seen by reference to
Fig. 1.
If the ratchet of the other switch B, be actuated, the current will pass as
indicated in Fig. 8, assuming that the other switches are in positions shown
in Fig. 6. In this case the current must pass from brush 14 to brush 13 of the
switch and thence to brush 9 of the switch A. If the ratchet of the switch A
farther to the right, be actuated, the current must pass from brush 8 to brush 9 as
indicated in Fig. 9 and finally reaching the brush 9 of the other terminal switch A,
the circuit being again broken. Again, if the switch A farther to the left be
actuated the current would have to pass from brush 9 to brush 8 as indicated
in Fig. 10, but as this is impossible if all the other switches are in the position
shown in Fig. 6, the circuit is again broken.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed, I declare that what I
claim is ;- =
1. In a circuit switch, the combination of a rotating ratchet composed of an
insulating disk and two conducting plates applied to its opposite faces, said plates
having lips bent to engage the teeth of the disk, the lips of each plate engaging
every alternate tooth, and four contact brushes, two of which are continuously in
engagement with the respective face plates of the disk while the other two
alternately engage the lips of the respective plates as the ratchet is actuated,
substantially as described."
2. In a system for controlling electric lights, the combination with the two
duplex or three wire switches, two conductors located between said duplex switches
and other switches interposed in the double portion of the circuit, each composed
of a rotating, insulating block, two contact plates, and four brushes, two of which

page_text: are in continuous engagement with the respective contact plates, and the other two
alternately in contact with said plates, substantially as described.
3. In a system for controlling electric lights, the combination with the circuit, of
two three wire switches, two conductors located between said switches, and one or
more four wire switches interposed in the double portion of the circuit, substantially
as described.
ALLISON BROS.,
Agents for the Applicant.