Improvements relating to Electrically Illuminated Signs or Advertisements.
Year: 1899

page_text: Date of Application, 19th Jan., 1899-Accepted, 25th Feb., 1899
COMPLETE SPECIFICATION.
Improvements relating to Electrically Illuminated Signs or
Advertisements.
I, WILLIAM LATTA CAMPBELL, of 52, Preston Street, Brighton, in the County of
Sussex, Jeweller 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 electrically illuminated signs or advertisements and
has for its chief object to provide simple and efficient automatic current distribut-
ing apparatus whereby pleasing and attractive lighting effects may be produced.
By my invention the lamps of the sign or advertisement may each successively
be made to glow for the same period, or by a simple device, the glow duration
of some of the lamps may be made longer than that of any of the remaining
lamps. Further, by using, in combination with the distributing apparatus afore-
said, lamps of various colours placed behind a translucent screen, pleasing colour
blending effects may be exhibited to the spectator as will hereinafter appear.
In order that my invention may be clearly understood, I will now describe the
same with reference to the annexed drawings in which similar letters refer to
like parts in all the figures, and wherein:
-
Figure 1 is a front elevation and Figure 2 a sectional side elevation of auto-
matic current distributing apparatus constructed and arranged according to my
invention. Figure 3 is a detail.
a is a snail cam of non-conducting material, such as ebonite, revolved by a
motor A. Essentials of the motor are that it should give a slow and steady speed
I consider as
to the cam aforesaid and be sensitive to retarding influences.
effective and simple a motor as any to be an ordinary clock movement A, as
illustrated, having its speed regulated by a fan bin lieu of by an escapement
and carrying the cam a on the hour wheel arbor. c is a flat peripheral contact,
of copper or other suitable conducting material, which covers a portion of the peri-
phery of the cam, abutting at one end against the step thereof, and is in con-
stant electrical connection with the source of current throughout the revolution
of the cam, through the quadrant and brush d, the latter being secured to the
ebonite or other insulating plate o fixed to the front of the clock movement, and
the former being suitably insulated from the cam spindle. is the wire by
which the brush d is connected with the source of current. Grouped around the
revolving eam and contact just described is a series of contact springs f arranged
so that they all have rubbing contact with the peripheral contact c aforesaid
In the drawings
when the cam revolves, and disposed at equal distances apart.
five contact springs are shewn but a greater or less number may be employed.
Each contact spring f is carried by a small plate g secured to the insulating
plate e aforesaid and is in electrical connection with a wire g¹ leading to a lamp
or group of lamps in the illuminated sign or advertisement. Each contact spring f
is provided with a suitable pressure regulating screw f¹ whereby its pressure on
the cam and contact c may be adjusted for the purpose hereinafter described.

page_text: As the cam a revolves in the direction of the arrow, the various contact springs f
successively drop onto and off the peripheral contact c thus cutting in and out
of circuit the various lamps with which they correspond. One reason for using
a snail cam in lieu of a disc for carrying the peripheral contact e is to provide a
step from off which the contact springs f may jump into sudden contact with c,
and it is obvious that an equivalent of this cam would be a disc having a trans-
verse rib or step a¹ formed on or secured to its periphery in juxtaposition to c
as shewn in Figure 3, this rib or step performing the same function as the rise
of the cam illustrated in Figure 1. Whatever the number of contact springs f
the length of the peripheral contact should be such that before any circuit is
broken another is closed, sparking is thus reduced, and since before any lamp is
cut out of circuit another lamp or lamps is cut in, pleasing colour blending effects
may be produced by using differently coloured lamps, as hereinafter set forth.
The contact springs f should be so adjusted or arranged as to bear with
moderate pressure upon the peripheral contact c and to just rest without pres-
sure on the concentric portion of the cam periphery after dropping off said con-
tact. The relative glow duration of the lamps may be varied as follows:-
Assuming that all the contact springs f bear with equal pressure upon any
point of the cam or peripheral contact surface, then, as the cam revolves, each
spring will make contact with the contact c for the same period of time and
each lamp will have the same glow duration, but let increased pressure be given
to any one of the springs f by means of its regulating screw f, then, as the rise
of the cam surface and the contact c pass this contact spring, the speed of the cam
will be retarded, and the said contact spring, together with those preceding it
which happen to be in circuit when the retarding action commences, will have a
longer period of contact with c than the others, the result being that the glow
duration of the lamps connected with such contact springs will be lengthened.
If the rise of the cam is very short and abrupt (the arrangement shewn in Figure 3
being the equivalent of this) retarding of the cam speed will of course not com-
mence until just before the braking contact spring drops into contact with c.
Preferably I employ lamps of different colours arranged within a convenient
box or casing and shielded by a screen of translucent (not transparent) material,
such as opal for example. Since as before mentioned, no lamp is cut out of
circuit until another has been cut in, pretty colour blending effects may be pro-
duced by tastefully arranging the order of succession of the different coloured
lamps, and the screen being translucent but not transparent, the spectator will
not the different colours but the colour effect produced by their blending.
A very effective arrangement for an advertisement or sign would be to place
the lamps behind the translucent dial or dials of a clock, the different colours,
their blending, and the variations in relative glow duration giving pleasing effects
and infallibly attracting attention.
see,
Having now particularly described and ascertained the nature of the said
invention, and in what manner the same is to be performed. I declare that what
1 claim is:-
-
1. The combination with electrically illuminated signs or advertisements and
the circuits thereof, of the automatically rotated snail cam or its equivalent, the
peripheral contact carried thereby and in constant electrical connection with the
source of current, and the series of contact springs grouped around the cam, all
constructed, arranged and operating together substantially as described and for
the purposes set forth.
2. The combination with electrically illuminated signs or advertisements and
the circuits thereof, of the automatically rotated cam or its equivalent, the peri-
pheral contact carried thereby and in constant electrical connection with the
source of current, the series of contact springs grouped around the cam, and the
pressure regulating screws applied to the contact springs, all constructed,.

page_text: arranged and operating together substantially as described and for the purposes
set forth.
3. In electrically illuminated signs or advertisements wherein the distribution
of current is effected by an automatically revolved contact carrying cam, or its
equivalent, and contact springs bearing on the periphery thereof; varying the
relative glow duration of the lamps by increasing the frictional pressure of one
of said springs, substantially as described.
4. In electrically illuminated signs or advertisements, the combination of
electric lamps of different colours shielded by a translucent but not transparent
screen, the lamp circuits, and current distributing apparatus as described, whereby
different colours and colour blends may be exhibited, the whole constructed,
arranged and operating substantially as set forth.
5. In electrically illuminated signs or advertisements, the employment or use
of automatic current distributing apparatus the various parts or elements of which
are constructed, arranged and combined, and operate together, substantially as
described with reference to and illustrated in the drawings.
1011
LT1000
E. P. ALEXANDER & SON,
Chartered Patent Agents,
19, Southampton Buildings, Chancery Lane, London, W.C., Agents.