IMPROVEMENTS IN ELECTRO-TELEPHONIC APPARATUS
Year: 1884

page_text: I, ALAN ARCHIBALD CAMPBELL-SWINTON of 43 Grove Street Newcastle upon
Tyne Engineer do hereby declare the nature of said Invention for "IMPROVEMENTS
IN ELECTRO-TELEPHONIC APPARATUS" to be as follows:-
My Invention relates to the transmitting portion of electro telephonic apparatus
and consists in arranging one part of the current regulators or variable contacts
themselves as pendulous hinged or suspended contact or contacts the other part
consisting of a fixed contact or contacts the parts being so combined that the
former bear upon the latter and the air waves due to the voice or other sound act
directly upon the pendulous hinged or suspended contact or contacts no diaphragm
or tympanum being used, the said contacts being simply enclosed in a case provided
with an opening for the voice or sound. The said pendulous hinged or suspended
contact or contacts may be hinged suspended or mounted in any suitable way and
so, if desired, that its or their degree of bearing on the other contact or contacts
may be varied.
Where a number of the pendulous hinged or suspended contacts
are used the current may be caused to flow through them in multiple arc or in
series.
J. HENRY JOHNSON,
47, Lincoln's Inn Fields, London, W.C.,
Agent for the said Alan Archibald Campbell Swinton.

page_text: -
I, ALAN ARCHIBALD CAMPBELL-SWINTON of 43 Grove Street, Newcastle-upon-
Tyne Engineer do hereby declare the nature of this invention for "IMPROVEMENTS
IN ELECTRO-TELEPHONIC APPARATUS " 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 the transmitting portion of electro-telephonic apparatus
and consists in arranging one part of the current regulators or variable contacts
themselves, as pendulous hinged or suspended and moveable contact piece or pieces,
the other part of the current regulators consisting of a fixed contact piece or pieces,
the parts being so arranged and combined that the former bear upon the latter,
and the air waves or vibrations due to the voice or other sound act directly upon
the pendulous hinged or suspended contact piece or pieces without the intervention
of a diaphragm or tympanum. The said pendulous hinged or suspended contact
piece or pieces may be hinged, suspended, or mounted in any suitable way, and
so if desired that its or their degree of bearing on the other contact piece or pieces
may be varied. Where a number of the pendulous hinged or suspended contact
pieces is used the current may be caused to flow through the said number in
multiple arc or in series.
And in order that my said Invention may be clearly understood I will now
proceed to describe means by which the same may be carried into practical effect
but I wish it to be understood that the details may be considerably varied without
departing from the nature of my Invention.
Figure 1 illustrates diagrammatically the arrangement of the contact pieces
according to my Invention, a is the moveable contact piece suspended from a wire
or rod or other support passing through a hole d in the upper part of the contact
piece a. b is the fixed contact piece against which the lower part of the contact
piece a bears. The current passes through da and b.
Figure 2 shews a modification wherein the moveable contact piece a is suspended
by a pin or wire d' let into the upper rod or block d and rests or bears against both
of the blocks or rods d and b which constitute the fixed contact pieces the wires
entering the instrument being connected to one of the said blocks or rods and the
wire leaving the instrument being connected to the other of them.
In Figure 3 the contact piece a is shewn suspended by a flexible conducting wire
or strip a² which is attached at its upper end to the support c and is in electric com-
munication with the conducting piece d-b is a fixed contact piece as in the other
figures.
In Figure 4 the moveable contact a is shewn suspended similarly to that in
Figure 3 but a² is not necessarily of conducting material and the contact piece a
rests or bears against two blocks or rods b and d constituting the fixed contact
pieces.
In Figure 5 the contact pieces b and d are placed on different sides of the move-
able contact piece a so that the resultant action of air pressure upon the piece a
causes it to press against both of the contacts b and d.
In the above Figures only one moveable contact piece is shewn but I prefer to
employ more than one arranged parallel to one another and in one plane the whole

page_text: bearing upon the same fixed contact piece or pieces so that the electric currents
pass through them in parallel circuits or multiple are but I may if preferred
arrange the apparatus so that the currents pass through the moveable contact
pieces in series that is to say one after the other or so that they pass through
several in a group in multiple are these groups being arranged in series.
The moveable and fixed contact pieces may be of any suitable conducting
material but those of considerable conductivity are preferable such for example as
carbon coke iron german silver bronze platinum aluminium or nickel.. They may.
also be of any convenient form either rectangular plates or blocks or bars or rods of
square oblong circular or eliptical section.
For the flexible pieces a² in figure 3 wires or foil of copper brass or steel or
other conducting strips or springs may be employed and for the same parts in
Figures 4 and the same material may be used but in this case the material need
not be conducting and therefore silk or other threads or tapes can be employed and
are in some instances preferable.
As shewn in Figures 6 and 7 the moveable and fixed contact pieces may be
arranged and mounted in a frame C of metal wood ebonite or other suitable
material. A number of moveable contact pieces a are here shewn strung upon a
wire d passing through their upper extremities their lower extremities resting
against the block or rod b constituting the fixed contact piece.
Where the frame C is of metal either bor d or both must be insulated from it to
prevent a short circuit.
The guard Z is to prevent the movable contacts d from shifting when the instru-
ment is being moved from place to place.
The degree of pressure primary existing between the fixed and movable contact
pieces may be varied in any convenient manner. For instance the movable pieces
may be pressed against the fixed ones by means of springs suitably applied or if
the movable pieces be of magnetic material magnets either permanent or electro
may be used for this purpose. I however find it most convenient to employ the
force of gravity alone, and I can then increase or diminish the primary pressure by
simply altering the inclination of the whole arrangement to the perpendicular
whereby great delicacy of adjustment can readily be obtained.
Figure 8 illustrates a modification wherein the frame C containing the fixed and
moveable contact pieces is mounted like a looking glass on vertical supports c³
attached to the base S and is so pivoted on these supports at x that its inclination
may be readily varied (and if necessary also fixed) at pleasure.
The suspending wire d is here connected by means of the conducting continua-
tion thereof (e) with one of the supports c³ which is in electric communication with
the terminal screw P¹ while the fixed contact piece 6 is similarly connected through
the other support with another terminal screw.
Figure 9 shews how the whole may be arranged when a containing case or cover
is employed.
Here the frame C is mounted opposite the opening or mouth piece G of the case
the said frame being hinged at x onto the fixed bracket or support c³ an adjusting
screw c, working in the support c³, and bearing against the triangular piece c³
attached to the frame C, affords a ready and convenient means for altering the
angle of C and the contacts carried thereby to the perpendicular.
S is the back board of the case, and the induction coil usually employed with
telephonic transmitters may conveniently be fixed at I.
It will be understood from the foregoing examples that the details and electrical
connections may be varied without departing from the nature of my Invention.
Having now particularly described and ascertained the nature of my said
Invention and in what manner the same is to be performed I declare that what
I claim is
First. In electric telephonic transmitters containing current regulators or con-
trollers operated directly by sound waves without the intervention of a diaphragm

page_text: or tympanum, the conbination with a fixed contact piece or several fixed contact
pieces of a pendulous hinged or suspended contact piece, or several such pieces
forming with the fixed piece or pieces current regulators substantially as herein-
before described.
Second. The several arrangements of Telephonic transmitting apparatus con-
taining pendulous hinged or suspended contact piece or several such pieces bearing
upon a fixed contact piece or fixed contact pieces substantially as hereinbefore
described with reference to the several figures of the accompanying drawings.
Dated this 25th day of September 1885.