IMPROVE. MENTS IN TELEPHONE RECEIVERS
Year: 1882

page_text: LETTERS PATENT to Willian Spence, of 8 Quality Court, Chancery Lane, in
the County of Middlesex, Patent Agent, for an Invention of "IMPROVE.
MENTS IN TELEPHONE RECEIVERS " Communicated to him from abroad by
Maximilien Kotyra, of Paris in the Republic of France.
PROVISIONAL SPECIFICATION left by the said William Spence at the
Office of the Commissioners of Patents on the 28th June 1882.
WILLIAM SPENCE, of 8 Quality Court, Chancery Lane, in the County of
Middlesex, Patent Agent. "IMPROVEMENTS IN TELEPHONE RECEIVERS," (being a
communication to me from abroad by Maximilien Kotyra, of Paris in the Republic
of France)
This invention consists in the adaptation and application to telephone receivers
of either compound magnets or simple magnets of the form herein after stated, such
telephone being susceptible of being completed with either a multiple or a single
magnet by a microphone.
The multiple magnet is composed of a series of bars fixed one over the other by
means of scrows, resistance coils with cores of soft iron being screwed into the
upper bar. This compound magnet or collection of magnets is or are inclosed in a
box of leather or other suitable material, the lid of which serves to secure the
vibrating plate of soft iron and in which lid is inserted the mouth piece of
caoutchouc. The same screws sorve to fix the magnet or magnets to the box and
to connect the box with the handle or ring.
Instead of the magnet being composed of a series of bars united by screws it
may be made of the same form in one piece. In either case the complete magnet
is oblong in shape with the upper part formed in two tongues which respectively
constitute the two poles which are thus brought near together, a space being left
between the said tongues and the lower part of the magnet. The ends of the poles
and the outer ends of the magnet and also the ends of the said spaces are curved
in plau or horizontal view. The said magnet whether compound or simple is a
permanent magnet to be used without a battery.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said William Spence in the Great Seal Patent Office on the
27th December 1882.
"
WILLIAM SPENCE of 8 Quality Court Chancery Lane in the County of
Middlesex Patent Agent
"
IMPROVEMENTS IN TELEPHONIC RECEIVERS Being a
communication to me from abroad by Maximilian Kotyra of Paris in the Republic
of France.
This Invention consists in the adaptation and application to Telephonic receivers
of either compound or simple magnets of the form or forms hereinafter described
.the invention being principally characterised by the construction of the steel
magnet and its armature of soft iron.
These magnets are composed of multiple bars separately magnetised and solidly
bound together; the polar extremities carry the soft iron cores or central parts of
the bobbins and the whole forms a magnet which is a sort of interrupted frame
The different modes of constructing a receiver with this magnet are represented
by the figures in the accompanying drawings.
6. e'.
a a'. a. (Fig. A B) are the multiple bars suitably fastened together by the screws
c. c' are the bobbins the soft iron cores b. 6' of which are carried by the
pular extremities of the magnet. f. is the box of leather i. its lid j. the vibrating
diaphragm, g. the mouth piece of India rubber or other suitable substance d. is the
ring or handle of the receiver.
Figures CD shew the general form of the magnet which in this instance is in
a single piece but it is preferred to employ multiple or compound magnets which
may also be variously constructed as shewn in other figures.
Before describing these figures it may be observed that a microphone of any
suitable kind may be combined with the teleplionic receiver.
It is also to be observed that the magnet whether compound or simple (multiple
or in a single piece) is a permanent magnet to be used without a battery.
The magnet represented in vertical section Fig: 1 and in plan Fig: 2 is
composed of overlying steel bars a (varying in number) the lowest bar being by
preference thicker than the others. Above these bars are two other bars or plates
of soft iron b. c. which are shorter so as to lie only on the ends of the steel bars.
Finally at the top are placed the soft iron bars d e. the free or projecting ends of
which, situated as shewn in relation one to the other in the centre of the magnet,
carry the soft iron spindles f. y. which are the cores of the bobbins h. i. "The
armature is thus constituted by the small flat plates of metal b. c. and by upper
plates f. g. Two screws k. I keep all the bars firmly together m. is the vibrating
diaphragm to be seen also in the other figures.
:
In Figures 3 and 4 which shew a vertical section and plan of the magnet the
steel bars a. are not changed but the soft iron plates b. c. (Fig 1) are dispensed
with, and the armature is constituted by the bent bars d. e. of soft iron the central
extremities of which are turned up vertically at right angles in order to form the
cores f. g of the bobbins.
Moreover these cores instead of being cylindrical have an elongated form (Fig: 4)
The screws k. l. serve the same purpose as before.
Fig 5 shews & slight modification of Fig: 1 the form of the magnet is not
changed but the flat plates of metal b. c. (Fig : 1) form part of the bars of soft iron

page_text: de and make one body with them; in other words these bars d. e. present each
an angle iron which takes the place of the bars of soft iron b. o.
In Figures 6 and 7 it will be seen that the bars d. c. have a particular form
they are curved at their extremities in the centre of the magnet being on a line at
right angles to the direction of the bars a. Besides these bars d. e are of steel;
they carry the soft iron cores f. g. of the bobbins-Lastly, they rest on the flat
plates of soft iron b. c which are similar to those in Fig: 1. This curving of
the steel bars d. e admits, by prolonging the bars, of having an increased magnetic
force with a diminished size of magnet.
-"
Figures 8 and 9 represent an arrangement which equally admits of having a
large magnetic force with a small space occupied by the magnet. This magnet is,
so to speak, embedded in a box of leather. It forms a sort of frame like the
former magnets. The hinder part of the frame is constituted by the steel bars a
laid together, the front face and a part of the sides are formed by the armature of
soft iron d. e the whole is kept together by the screws k. l. On the ends of tho
pieces d. e. at the central part of the magnet are screwed the angle irons of soft
iron n. p intended to support the cores f.g of the bobbins. The drawing shews
this mode of construction in other respects.
It is to be observed that the arrangements described above by way of illustration
are susceptible of modification in detail. Thus the bars a. of the magnets may be
more or less thin and combined in a greater or less number. The magnet may be
made throughout of steel carrying only the cores of the bobbins of soft iron or
a varying number of flat plates of soft iron may be combined with the steel bara
as described. Lastly, the magnet may be formed in a single piece.
The system or kind of magnet herein before described when applied to a
telephone is adapted to be used as a substitute for other magnets in telephonic
instruments It has been shewn as used in receivers, but it is equally applicable
to transmitters; the construction of transmitters and receivers being identical under
the present system the same apparatus may be used indifferently for transmitting
or receiving sounds.
If it be desired to combine together a receiver and a transmitter in order to form
a single apparatus it will be sufficient to fasten two magnets together at their base
either separating them by a non electric material (leather or other substance) or
not when sounds can be transmitted from one side and received at the opposite
side. It is not necessary to enter into greater detail as to the numerous
combinations that can be made.
Having thus described the nature of the said Invention and in what manner
the same is to be performed communicated to me from abroad as aforesaid I
hereby declare that what I claim as of the said Invention is :--
First-The construction of a magnet with multiple steel bars forming an
interrupted frame and carrying on the intersected sides of the frame the soft iron
cores of the bobbins
Secondly: In such a magnet the combination with the steel bars of flat plates
of soft iron and bars also of soft iron forming an armature substantially as
described with reference to Figures 1 and 2.
Thirdly: In such a magnet the combination with the steel bars of flat plates of
soft iron bent or turned up at their inner ends in order to form the elongated cores
of the bobbins substantially as described with reference to Figures 3 and 4.
Fourthly: In such a magnet the curved form of the upper steel bars which
carry the soft iron cores of the bobbins substantially as described with reference
to Figures 6 and 7.
Fifthly: In such a magnet the combination with the steel bars at the right
hand of two bent pieces of soft iron forming an armature and carrying at their
inner extremities the soft iron cores of the bobbins which cores can be directly
screwed thereto (Fig: 5) or connected thereto by intermediate angle irons of soft
irou as in Figures 8 and 9.

page_text: And lastly-The use of a magnet or magnets constructed in the mauner
substantially as described and the combination of two or more of such magnets
in a single apparatus.
In witness whereof I the said William Spence have hereunto set my hand
and seal the twenty seventh day of December in the year of our Lord
One thousand eight hundred and eighty two.
Witness
W. H. SPENCE
8 Quality Court
Chancery Lane
WILLIAM SPENCE (L.S.)