Improvements in Raising and Lowering the Light of Electric Glow Lamps.
Year: 1893

page_text: Date of Application, 11th Sept., 1893 -
Complete Specification Left, 11th June, 1894-Accepted, 1st Sept., 1834
PROVISIONAL SPECIFICATION.
Improvements in Raising and Lowering the Light of Electric
Glow Lamps.
I, THOMAS BUDWORTH SHARP of County Chambers Martineau Street
Birmingham Mechanical Engineer do hereby declare the nature of this invention
to be as follows :-
In electric glow or incandescent lamps it has hitherto been the custom to reduce
their brilliancy either by shading then or passing the current through resistance
coils. Now, both these methods waste the current and
my invention has for its object
the avoidance of this waste and I carry it out thus :-Glow lamps (when there are
more than one) are either connected in series or in parallel, but, I will first describe
my invention as applied to two lamps.
With a constant voltage two lamps in series give a lower light than two lamps in
parallel, as is well understood and at the same time use less current, and I take
advantage of these well known facts and connect my lamps both ways that is in
series as well as in parallel and arrange my switch or switches so that I can run
the current either way or shut it off altogether.
When I want the lamps to give their maximum light I switch the current on
for "parallel" and when I want a reduced light I switch it on for "series" and
get less light and use less current.
Though I have spoken of two lamps my invention is applicable to more and if I
put more than one filament into one lamp and connect the said filaments both for
series and parallel it may even be applied to one lamp.
By another modification of my invention I can switch from two or more in series
to any greater number in series than I usually work in series and produce like
results. This modification is applicable to those installations which work at a
higher voltage and with two or more lamps in series.
Dated this 8th day of September 1893.
THOMAS BUDWORTH SHARP.
COMPLETE SPECIFICATION.
Improvements in Raising and Lowering the Light of Electric
Glow Lamps.
I, THOMAS BUDWORTH SHARP of County Chambers Martineau Street,
Birmingham, Engineer 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 :-
In electric glow or incandescent lamps it has hitherto been the custom to reduce
their brilliancy either by shading them or passing the current through resistance
coils-now; both these methods waste the current and my invention has for its
object the avoidance of this waste and I carry it out thus:-Glow lamps when
there are more than one are either connected in series or in parallel but I will first
describe my invention as applied to two lamps
With a constant voltage two lamps in series give a lower light than two lamps in
parallel, as is well understood, and at the same time use less current and I take
advantage of these well known facts and connect my lamps both ways that is in
D
0

page_text: "
series as well as in parallel and arrange my switch or switches so that I can run the
current either way or shut it off altogether.
When I want the lamps to give their maximum light I switch the current for
'parallel" and when I want a reduced light I switch it on for "series" and get less
light and use less current. Though 1 have spoken of two lamps my invention is
applicable to more, and, if I put more than one filament in
connect the said filaments both for series and parallel it may even be applied to
one lamp.
one lamp and
By another modification of my invention I can switch from two or more in series
to any other number in series greater than the minimum number I usually work in
series and produce like results.
I will now describe more particularly how my invention is to be carried out.
In switching from parallel to series I wire as on Sheet 1 where A and B are
glow lamps and C is the base of a switch (to be more fully described later on).
On this sheet the shaded parts of the switch base are slate and the unshaded parts
brass. The positive and negative poles are marked respectively + and -. Now
it is evident that (when C¹ is electrically connected with C and C³ is electrically
connected with C) the current entering at C¹ will partly pass through the lamp A
by means of the wires C¹ A¹ and A' C and then away through the wire connected
with C. The other portion of the current which has entered at C₁ will pass
through the lamp B through the agency of the wires C B and B C and away
by the wire connected with C. Thus the lamps A and B are in "parallel" and
"full on."
It is also evident that if I cut the electrical connection between C1 and C' and
between Cand C and electrically connect C³ and C³ then the current entering
at C' will pass through the lamp Å by means of the wires C¹ A' and A C³, after
that it will pass through the lamp B by means of the wire C B¹ and B* C* and
away by the wire leaving C₁.
Thus the lamps A and B are in "series" and only "part on."
"
Of course I may add as many lamps as I deem fit to the wires C¹A¹
and AC and the same number to the wires C B₁ and B° C and the effects
produced on each lamp will be the same as the effects produced on the lamps A
and B.
An enlarged view of one form of switch which produces these effects is shewn on
Sheet 2 in elevation and plan (outside view) and on Sheet 3 is its end view while
on Sheet
it is shewn in sectional elevation and with a plan of the base only. The
same letters refer to the same parts throughout these three drawings.
CC is the slate or other non-conducting base: C1, C2, C and C are the brass
pieces attached to the base: D, D are the joints or hinges on which the sides DE
and the handle F turn or rock: G G G are brass discs or bobbins for the purpose
of electrically connecting or dis-connecting C1 and C2, C3 and C³, C3 and C as the
case may be. When the rocking arrangement is vertical or nearly so all the lamps
are out; when it inclines to that side of the base marked H the lamps are all full
on or in parallel and when it inclines towards that side of the base marked I the
lamps A and B are only a little on or in series.
The advantages which this plan has over the well known plan of having an
extra or dead lamp in connection with each live lamp which is usually full on are
two fold.
Let us take the case of a 32 C.P. lamp in a bed-room or railway carriage
When at night only a little glimmer is required, it has sometimes been the custom
instead of using the usual and wasteful resistance to have an extra 32 C.P. lamp
which may at will be thrown into series with the one which is usually full on
but this is unsightly and clumsy compared with my plan in which two 16 C.P.
full on lamps take the place of one 32 C.P. lamp full on and one 32 C.P. lamp out
or dead.
Next take the economy 1 effect-The smallest glimmer is all that is required
when in bed or sleeping in a railway carriage. Now say for the sake of argument

page_text: that one 32 C.P. lamp uses 1.25 amperes; if the dead 32 C.P. is now thrown into
series with it the pair will be found to be using say 5 of an ampere; but my
or in parallel
two 16 C.P. lainps which also use 1.25 amperes when full on
only use 25 of an ampere when part on or in series (in other words half the
quantity).
I will next describe how I switch from one series to another without having any
resistances or dead lamps. Take the case of a cluster of six lamps for dining
drawing and other rooms.
There are times when a somewhat more subdued light is required so I wire
my six cluster and arrange my switch in such a manner that I can have either
3 lots of two in series or two lots of 3 in series. Say I am working at 110 volts :
when full on I use 55 volt lamps: two in series: when I want a somewhat more
subdued light I cut out one pair & divide it (the said pair) between the remaining
pairs thus I have now two lots of 3 in series. This is where my saving comes
in over the usual resistances: I utilize the resistance for giving light in other
words I make some of the lamps act as resistances to the others but the heat
generated is not wasted but reappears as light in those lamps which I have
cut out.
The wiring of this particular cluster is shewn on Sheet 5: the outside elevation
of a suitable switch for the job is shewn on Sheet 6: its plan on Sheet 7: its end
view on Sheet 8: Sheet 9 shews the handle, rocker and bobbin in sectional
elevation while Sheet 10 shews a plan & sectional elevation of its base.
:
The designing of the switches is merely a draughtsman's job: their various forms
are legion: so, I have only troubled to describe in detail one-viz. -the one 1
use for switching from series to parallel.
With a six cluster only two useful effects can be obtained-namely-3 lots of two
in series alterable to 2 lots of 3 in series.
With a 12 cluster 3 useful effects can be obtained-namely-6 lots of two in
series-alterable to 4 lots of 3 in series-which in its turn is again alterable to
6 lots of 2 in series.
With a 60 cluster (or row as for footlights) 4 useful effects can be obtained—
namely 20 lots of 3 in series-alterable to 15 lots of 4 in series-again alterable
10 12 lots of 5 in series-which are again alterable to 10 lots of 6 in series, and so
90. I do not necessarily produce my various series effects with a single switch
sometimes I employ several: it being inerely a matter of electrically severing some
wires and joining others.
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. The method of wiring electric glow lamps and arranging their switches so
that they may be run either in parallel or series-without having any of the said
lamps out or dead-substantially as described and illustrated and for the purposes
set forth.
2. The method of wiring electric glow lamps and arranging their switches so
that they may be run in batches of various numbers in series-provided those
numbers are evenly divisible into the total number of the lamps-without having
any of the said lamps out or dead-substantially as described and for the purposes
set forth.
Dated this Ninth day of June 1894.
THOMAS BUDWORTH SHARP.