IMPROVEMENTS IN ELECTRIC BELL APPARATUS
Year: 1872

page_text: LETTERS PATENT to David Graham, junior, of Glasgow, in the
County of Lanark, North Britain, Bellhanger, for the Invention of
"IMPROVEMENTS IN ELECTRIC BELL APPARATUS."
Scaled the 13th September 1872, and dated the 18th March 1872.
PROVISIONAL SPECIFICATION left by the said David Graham at the
Office of the Commissioners of Patents, with his Petition, on the
18th March 1872.
I, DAVID GRAHAM, junior, of Glasgow, in the County of Lanark,
North Britain, Bellhanger, do hereby declare the nature of the said
Invention for "IMPROVEMENTS IN ELECTRIC BELL APPARATUS," to be as follows,
that is to say -
This Invention has for its object to render electric bell apparatus
more efficient, durable, and convenient than as hitherto made and less
liable to get out of order.
The Invention consists in combining an improved electric current
producer or electric battery with improved indicating apparatus to be
used where one bell is to be acted on by two or more wires, and with an
improved contact maker for putting the apparatus in action when
required.

page_text: The improved electric battery consists of one or more cells, each of
which is of glass of a cylindrical or other suitable form. Each cell has
placed on the bottom of it a disc of copper, or of lead, or other suitable
metal, on which copper will be deposited by a solution of copper sulphate.
A grating shaped piece of zinc is placed at a little distance above the
copper, being conveniently supported by lugs which are formed on it
and rest on the edge of the glass cell. An earthenware cup or dish is
rested on the zinc, and a tube which is formed projecting down from
the centre of the bottom of the cup passes down through a central hole
in the zinc to within about an inch of the copper beneath. Parchment,
paper, or a permeable-membrane or other suitable permeable material is
applied over the bottom and round the sides of the zinc, to act as a
porous cell, and the usual copper conducting wires or electrodes are
fixed to the copper and zinc, being by preference covered with gutta
percha in the cell, and to some little distance away from it. The cell
is completed by filling in solution of zinc sulphate and placing crystals
of copper sulphate in the earthenware cup; and when the apparatus is
to be used on board ship or to be carried about the cell is filled with

page_text: rung on the closing of the circuit through any one of the several com-
municating wires, whilst the dropping of the corresponding knob will
indicate which wire is used in any case. It will be the duty of those
attending to the communications to lift the dropped knob or knobs to
their upper positions.
The improved contact maker for actuating the bell consists of an
olastic metallic diaphragm which is fixed over a cavity in a picce of
wood or other suitable non-conductor, one of the circuit wires being put
in metallic communication with the diaphragm and the other with a.
metal button in the cavity. The diaphragm, which may have a projec-
tion or button formed or fixed on its contre, is fixed so as not to touch
the inside button when left to itself, but is put into contact therewith
by a slight pressure of the thumb or finger, springing out from contact
again when the pressure is removed. The diaphragm thus acts as a
spring, and at the same time covers in the cavity and prevents moisture
or dust from getting at the contact surfaces, thus keeping them per-
manently in working order. In some cases screw clips are fixed on
the wood oase of the contact maker in separate metallic communication
with the two circuit wires, so that wires can at any time be attached to
communicate with a portable contact maker, an arrangement of con-
siderable utility and convenience in various cases, as for example in a
sick room.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said David Graham in the Great Scal Patent Office
on the 17th September 1872.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, DAVID
GRAHAM, junior, of Glasgow, in the County of Lanark, North Britain,
Bellhanger, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Eighteenth day of March, in the year of our
Lord One thousand eight hundred and seventy-two, in the thirty-fifth
year of Her reign, did for Herself, Her heirs and successors, give and
grant unto me, the said David Graham, junior, Her special licence that.
I, the said David Graham, junior, my executors, administrators, and
assigns, or such others as I, the said David Graham, junior, my

page_text: executors, administrators, and assigns, should at any time agree with, and
no others, from time to time and at all times thereafter during the term
therein expressed, should and lawfully might makė, use, exercise, and
vend, within the United Kingdom of Great Britain and Ireland, the
Channel Islands, and Isle of Man, an Invention for "IMPROVEMENTS IN
ELECTRIC BELL APPARATUS," upon the condition (amongst others) that I, the
said David Graham, junior, my executors or administrators, by an instrų-
ment in writing under my, or their, or one of their hands and seals, should
particularly describe and ascertain the nature of the said Invention, and
in what manner the same was to be performed, and cause the same to
be filed in the Great Seal Patent Office within six calendar months next
and immediately after the date of the said Letters Patent.
NOW KNOW YE, that I, the said David Graham, junior, do hereby
declare the nature of my said Invention, and in what manner the same
is to be performed, to be particularly described and ascertained in and
by the following statement in writing, reference being had to the
accompanying Drawings, that is to say:
My said Invention has for its object to render electric bell apparatus
more efficient, durable, and convenient than as hitherto made and less
liable to get out of order.
My Invention consists in combining an improved electric current
producer or electric battery with improved indicating apparatus to be
used where one bell is to be acted on by two or more wires, and with an
improved contact maker for putting the apparatus in action when
required.
And in order that my said Invention and the manner of performing
the same may be properly understood, I hereunto append a Sheet of
explanatory Drawings, to be herein-after referred to, and representing a
modification of my improved electric bell apparatus. In these Drawings
the same reference numerals are used to mark the same or like parts
wherever they are repeated.
Figure 1 is a vertical section of one cell of the improved electric
current producer. The parts of this cell are contained in a vessel 11,
which is by preference of glass of a cylindrical or other suitable form,
and comprise a disc 12 of copper or of lead or other suitable metal, on
which copper will be deposited by a solution of copper sulphate. A
grating shaped piece of zinc 13 is placed at a little distance above the

page_text: copper, being conveniently supported by lugs 14 which are formed on
it and rest on the edge of the glass cell 11. An earthenware cup or
dish 15 is rested on the zinc 13, and a tube 16 which is formed projecting
down from the centre of the bottom of the oup passes down through a
central hole in the zino to within about an inch of the copper 12 beneath.
Parchment paper 17 (colored blue in the Figure), or a permeable
membrane or other suitable permeable material is applied over the
bottom and round the sides of the zinc 13 to aot as a porous cell, and
the usual copper conducting wires or electrodes 18, 19, are fixed to the
copper 12 and zinc 13, being by preference covered with gutta percha
in the cell and to some little distance away from it. The cell is com-
pleted by filling in solution of zinc sulphate and placing crystals of
copper sulphate in the earthernware cup 15.
When the apparatus is to be used on board ship or to be carried about
the cell is filled with sawdust, and is by preference constructed and
arranged in the somewhat modified form shown in vertical section in
Figure 2. An inverted earthenware cup 20 is connected by a tube 21
to the bottom tube 16 of the upper cup 15, and this lower cup 20 has
its upper surface perforated and the parchment paper or membrane 17 is
placed over it instead of round the zinc 13. The sawdust is packed into
the spaces outside of the cups 15, 20, and to reduce evaporation a
compound of resin and grease is run upon the top of the sawdust round
the upper cup 15, whilst a disc or cover of earthenware or wood may be
applied to the cup itself. The cup 15 is formed with a spout 22 at the
side to fill in liquid by and to give egress to any gas generated in the
cell.
An example of my improved indicating apparatus is shown in Figures
3, 4, 5, Figure 3 being a front view of the case in which it is arranged,
Figure 4 a transverse vertical section, and Figure 5 a view with the
front removed. The front 23 of this case is formed with a number of
vertical grooves 24 corresponding to the number of wires in connection
with one bell 25 (shown in Figure 6), and a name, number, or mark is
applied at each groove to tell the room, cabin, or locality corresponding
to each wire. In each groove 24 there is fitted to slide easily a knob 26,
having fixed to the back of it inside the case a metal slide 27 formed
with a catch projection, and when the knoh is lifted up to the top of the
groove this projection catches upon a corresponding projection on a strip.
of iron 28 held by a spring blade which gives it a tendency to engage

page_text: with the knob catch. The strip of iron 28 is adjusted within attracting
distance of two small electro-magnets 29 (or one larger one), which when
put into action draw it back and thereby occasion the falling of the
knob 26. The wrapping wire (shown in red) of the electro-magnets 29
is made part of the circuit by which the bell 25 is set a going, and
similar arrangements are repeated in connection with each indicating
knob 26, or in other words in connection with each communicating wire.
The wrapping wires of the several electro-magnets 29 have each one
end 30 joined to its respective communicating wire 31, but all the other
ends 32 are joined to a single conductor 33, which is in this example
a strip of copper, and has connected to it a wire 34 that proceeds-onwards
to the bell 25. The bell will thus be rung on the closing of the circuit
through any one of the several communicating wires 31, whilst the
dropping of the corresponding knob 26 will indicate which wire is used
in any case. It will be the duty of those attending to the communi-
cations to lift the dropped knob or knobs 26 to their upper positions.
My improved contact maker for actuating the bell is shown in front
view in Figure 7, and in section in Figure 8. It consists of an elastic
metallic diaphragm 35 fixed over a cavity 36 in a piece 37 of wood or
other suitable non-conductor, one of the circuit wires 31 being put in
metallic communication with the diaphragm 35 and the other 38 with a
metal stud 39 in the bottom of the cavity. The diaphragm 35, which
may be conveniently made of the requisite elasticity by being formed of
thin sheet metal with concentric circular corrugations and which may
have a button formed or fixed on its centre, is fixed so as not to touch
the inside stud 39 when left to itself, but is put into contact therewith
by a slight pressure of the thumb or finger, springing out from contact
again when the pressure is removed. The diaphragm 35 thus acts as a
spring and at the same time covers in the cavity 36 and prevents moisture
or dust from getting at the contact surfaces and keeps them permanently
in working order. In some cases, as is shown in Figure 9, screw
clips 40, 41, are fixed on the wood case 37 of the contact maker in
separate metallic communication, one with the diaphragm 35, and the
other with the stud 39, and through these parts with the respective
circuit wires 31, 38, so that wires 42 can at any time be attached to the
fixed contact maker to communicate with a portable contact maker 43,
an arrangement of considerable utility and convenience in various cases,
as for example in a sick room. The bell delineated in Figure 6 is of the

page_text: ordinary construction, and is shown merely to admit of the manner of
combining the various parts of the entire apparatus being exhibited:
The circuit or connecting wires are shown in red, it being of course
understood that they may be of any convenient length, and that the
various parts may be placed in any convenient situations.
Having thus particularly described my said Invention, and the manner
of performing the same, I have to state that I do not restrict myself
to the precise details herein described or delineated; but that what I
believe to be novel and original, and claim as the Invention secured to
me by the herein-before in part recited Letters Patent is,―
1. The arranging or combining together of the parts of electric bell
apparatus substantially in the improved manner herein described and
delineated.
2. The forming of a portable electric battery cell substantially in the
improved manner herein-before described more particularly with reference
to Figure 2 of the accompanying Drawings.
3. The combining of two or more circuit wires with a single electric
bell and with improved indicating details substantially such as are
hercin-before described with reference to Figures 3, 4, 5, of the accom-
panying Drawings.
4. The constructing of electric contact makers substantially in the
improved manner herein-before described with reference to Figures 7, 8,
9, of the accompanying Drawings.
In witness whereof, I, the said David Graham, junior, have here-
unto set my hand and scal, this Sixteenth day of September,
in the year of our Lord One thousand eight hundred and seventy-
two.
Witness,
0 EDMUND HUNT, .
Patent Agent,
Glasgow.
DAVID GRAHAM, JR. (L.S.)