Improvements in Mechanical Telephones.
Year: 1890

page_text: Date of Application, 21st Jan, 1890-Accepted, 19th Apr., 1890
COMPLETE SPECIFICATION.
Improvements in Mechanical Telephones.
I, ROBERT CALDWELL MACKEY BOWLES, of the Norfolk House Eliot Square in
the City of Boston, in the County of Suffolk, and State of Massachusetts, United
States of America, Gentleman, do hereby declare the nature of my invention and in
what manner the same is to be performed, to be particularly described and ascertained
in and by the following statement :-
I have conceived the idea of so constructing a telephone that it can be almost
instantaneously attached to any point in a telephone line where desirable or
practicable.
My invention consists in suspending or holding the telephone upon the line wire
without other support than the wire itself, and then providing means for holding the
diaphragm of the telephone under a tension equal to or proportionate to that line
wire, and it further consists in providing means for adjusting the tension of the
diaphragm.
I have accomplished this object by the device of connecting the line wire with the
diaphragm of the telephone through a double funnel-of metal or wood-of any
desired length-from an inch or less-upwards, the lower funnel being of the same
diameter as and, at its perimeter, resting upon, the diaphragm. One funnel may
rest directly upon the other, or they may be connected by a hollow shaft, of any
desired length. In cases where but a short connection is to be made, say of two or
three inches or less, the double funnel being constructed in accordance, I pass through
the two funnels and through the centre of the diaphragm beneath, a connecting rod,
with its upper end formed as a hook and its lower end as a screw. I then place upon said
connecting rod a washer, and upon that, working on the said screw-end of connecting
rod, an adjusting nut. In the upper funnel and on opposite sides thereof are provided
slots say a balf-inch in depth to receive the line wire. Between said slots on both sides
of the funnel near the top suitable holes are made in which are placed insulated or
insulating wires or cords firmly secured in position and extending across the funnel
at right angles to the line of the line wire slots. When the instrument is to be
connected with the line wire that wire is secured in the slots, by passing over said
line wire the book of connecting rod, the line wire resting upon the insulated wire
cords, and turning upon the adjusting nut until said line wire, funnel and diaphragm are
firmly and rigidly drawn together and the proper tension given to the diaphragm.
When a longer attachment to the line wire is desired, I connect the two funnels by
means of a hollow shaft or tube and connect the connecting rod and line wire by a
wire, to one end of which is attached a double link of chain and to the other end a
hook; hook the connecting rod to the double link of chain and pass the hook of said
connecting wire over the line wire, and then, as in the case of the short connection-
turn the adjusting nut till all the parts are drawn together-in tension.
In the drawings herewith and forming part of this Specification, Fig. 1 shows a
Telephone Line with the two forms of my device, as described, thereon.
Fig. 2, shows a cross-section of my device, when the short connection with line
wire is adopted; bb being the upper funnel with the slots c c therein and per-
forations c, c through which pass the line-supporting insulated wires 11. L is the
line wire-C the connecting rod with its hook-end, d, and screw-end, e,-B the
diaphragm, f, the washers and D, the adjusting nut.
Fig. 3 shows a cross-section of my device, where a long connection with the line
wire is desired.
The parts thereof corresponding with those in Fig. 2 are represented by same
letters. A, A, represents the hollow shaft or tube connecting the funnels a and b
F, the connecting line or wire with its double-link of chain or chain links, h, at

page_text: lower end and its hook g at upper end. E represents the transmitter with frame,
and the screws and nuts by which funnel, diaphragm and transmitter frame may be
clamped together.
I have described the line supports held in the perforations c, c, as insulated or
insulating wires or cords; but covered wires or catgut cords or their equivalent may
be used without loss of efficiency.
The instruments weigh but a few ounces, and as they turn easily upon the line,
they readily adapt themselves to the stature of any one.
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 :
1st. A mechanical telephone suspended on its line wire, and provided with means
for holding the diaphragm under tension equal or proportionate to the tension of the
line wire substantially as and for the purpose described.
2nd. A mechanical telephone suspended on its line wire, and provided with means
for holding the diaphragm under tension proportionate to that of the line wire, and
means for adjusting the tension of the diaphragm, substantially as and for the purpose
described.
3rd. The combination in a mechanical telephone and line wire of the funnel a, a,
funnel b, b, with slots c¹, c², line wire supports held in perforations c, c, connecting
rod C, and diaphragm B, substantially as described and shown.
4th. The combination in a mechanical telephone and line wire of the double
funnel, a, a, connecting hollow shaft or tube A, A, funnel b, b, with slots c¹, c¹, line
wire supports beld in perforations c, c, diaphragm B, connecting rod C with hooked
end d, threaded end e, washer f, and adjusting nut D, connecting line or wire F,
chain links and hook g substantially as shown and described.
Dated this Twentieth day of January 1890.
CRUIKSHANK & FAIRWEATHER,
62, Saint Vincent Street, Glasgow, Agents.