Improvements in Switches for Telephone Circuits.
Year: 1891

page_text: Date of Application, 25th Feb., 1891
Complete Specification Left, 8th Sept., 1891-Accepted, 10th Oct., 1891
PROVISIONAL SPECIFICATION.
Improvements in Switches for Telephone Circuits.
We CHARLES HERBERT ELLIOT of Elmers End near Beckenham, in the
County of Kent, Electrical Mechanician, and ERNEST FRANK FURTADO of
Number 6 Queen Street, Edgware Road, London, Electrical Mechanician do
hereby declare the nature of this invention to be as follows:-
The object of the present invention is to provide a switch whereby a number of
telephone stations can call each other without first calling to a central point, and
furthermore to so arrange that on hanging up the receiver the switch shall auto-
matically return to the individual line belonging to the instrument, to be in readiness
for the next call.
According to our invention, we take a disc wheel or other suitable device, upon
one face of which is fixed the switch arm, and upon the other or inner face, and on
the centre thereof, an oblong boss, which is gripped across its shortest length by a
pair of tweezer springs. Then round the circumference of the said disc wheel or
other suitable device, and firmly gripping thereon is fixed a band break; the free
end of which is capable of being sprung outwards by the upward pressure of one
arm of a rocking lever; the arm of the said lever terminating in a hook upon which
the receiver is placed when the instrument is at rest.
Now, when the switch arm is turned to make contact with another line and the
receiver is removed from the hook, the break will grip upon the disc wheel or other
suitable device by reason of the upward pressure of the hook lever being removed
from the break keeping the tweezer springs sprung open across some larger
diameter of the said boss, and so keeping the switch arm resting on the required
contact: but immediately the receiver is replaced upon the hook it brings up the
inner arm of the lever, springing up the break, thereby releasing the above
mentioned disc wheel or other suitable device of its pressure; and the tweezer
springs, finding it free to revolve, force the said boss round until its smallest diameter
lies in a horizontal line between the springs and the switch arm covers the zero or
home point.
Dated this 24th day of February 1891
ERNEST FRANK FURTADO..
COMPLETE SPECIFICATION.
Improvements in Switches for Telephone Circuits.
We, CHARLES HERBERT ELLIOT of Elmers End, Beckenham, in the County
of Kent, and ERNEST FRANK FURTADO of 6 Queen Street, Edgware Road,
London, W. Electrical Mechanicians 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:—
Our invention relates to improvements in telephone switches, and applies more
particularly to those known as "compound switches" that is to say, a switch
capable by its adjustment of being placed in circuit with more than one line, or
several alternately, and consists mainly of an improved device whereby the home
instrument may be automatically placed in electrical and signal contact with all the
circuits connected thereto by the simple hanging up of the receiver after use.
We are aware that compound telephone switches are not novel, and we wish it
understood that we do not claim as our present invention any specific means of
arranging the circuits or contacts therein or therefrom but may adopt any of the

page_text: well known devices for attaining this, after the manner of such switches generally,
and we are further aware that such switches have been constructed hitherto with a
means for automatically placing the home signal in line with each circuit after use,
but we are not aware that any instrument exists prior to our invention whereby the
home signal may be automatically placed in electrical communication with every
telephone station connected thereto, by the simple method and means employed by
us, and forming the subject of our present invention.
Our invention consists essentially of a disc, wheel or other device, upon the axis
of the outer face of which is fixed a pointer, switch arm. or contact maker, capable
by its oscillations of being placed upon, and in electrical contact with, any one of a
series of metallic discs forming the terminals of the lines from the various stations
the instrument is in telephonic, and electrical signal communication with. Upon
the axis of the other, or back face of said disc, or other device, is an oblong boss,
which is gripped across its shortest diameter by a pair of tweezers, or spring fork,
the tension of which tends to keep said oblong boss in a vertical position, parallel to,
and in line with the prongs thereof. Partly surrounding and firmly gripping the
.outer periphery of said disc or other device, we place a band, preferably metallic,
which acts as a brake therefor when tightened by the depression of one end of a
pivotted lever arm to which one end of said band is attached, and is released, or
sprung upwards clear of said disc, wheel or other device when the same end of the
lever is raised, and this occurs by the depression of the opposite end thereof, which
terminates in a hook outside the side of the switch board and upon which the
receiver is placed after use, and by the weight of which said lever arm is depressed,
and the instrument automatically placed at zero or upon the home signal circuit by
reason of the spring tweezers forcing the oblong disc, and consequently the pointer,
.or contact maker into a vertical position, and in electrical contact with the terminal
of the home signal circuit.
In order that our invention and the manner of its operation may be clearly under-
stood, we have appended hereunto a sheet of drawings, in which,
Fig. 1 is a front view of a compound switch board constructed according to our
invention.
Fig. 2 is a back view, and Fig. 3 is a vertical section of same.
Figs. 4 and 5 are enlarged and slightly exaggerated views intended to more
clearly illustrate the automatic operations of the spring fork, and brake band,
forming the salient points of our invention.
Similar letters of reference indicate like parts throughout the drawings.
In carrying our invention into effect we construct of any suitable non-conducting
material a switch board A, preferably of the form or configuration shewn by the
drawings, upon the back of which we mount a recessed circular or partly circular
disc, wheel or other metallic device B, one end of the spindle of which a, passes
through A, and a suitable bush b, and carries upon its outer end in front of A, a pointer
or contact maker C, made of any suitable electrical conducting material, preferably
brass, and furnished with a handle C, and is retained upon a by means of a nut,
screw or the like c The opposite end of a is formed with an oblong boss d the
greatest diameter of which is in line with C. Upon the back of A we fix by means
of screws or the like, a vertical spring fork or tweezers D, encompassing the
narrowest width of d, the tension or grip of D tends to keep d and consequently C
in a vertical position. Upon the front of A we fix a crescent shaped strip of
insulating material E, or form the same integrally with, and of the same material
as A, and insert therein any number of metallic dises e, flush with or slightly raised
from the face of E, so that C may be in rubbing and electrical contact with either
as needed. Each of the discs e is connected to or formed with a screw stud which
passes through E and A, and is held in position by a nut screwed thercon at the
back of A. The number of discs e represent the mumber of stations the switch board
is capable of being electrically connected with and these may be numbered, lettered,
or carry any design or distinctive mark by which the particular station to which
each belongs may be known, the line wire from which would be connected thereto

page_text: at the back of A as shewn in Fig. 2.
The centre disc el, or that covered by C,
when in a vertical position as at Fig. 1, would be the home point or zero, and upon
which Crests when the instrument is not in use telephonically, in readiness to
receive the signal of attention from either station, suitable contact being made
between e', and a self contained bell or its equivalent placed in any suitable position
upon A, preferably that shewn by the dotted outline F, Figs. 1, and 3, for that
purpose.
Upon the back of A is a lever arm G, pivotted at /, one en of which passes
through a slot in the side of A and terminates in a hook g. To the lever arm G
ath, is connected one end of a band brake H, preferably metallic, which passes
partly around the outer periphery of B, and fastened to bracket or the like I
upon A. To the lever arm G, at the opposite end from is attached an adjustable
spring J, the tension of which gives a downward pull to G and tightens H
upon B. The hook is for the reception of the receiver K, and when this is
upon . G is by its weight brought to a horizontal position as at Fig. 1.
It will be understood that the raising of g by the removal of K, lowers the
opposite end of G, and tightens H upon B, as in Fig. 5 and retains B in any
position desired, and that the lowering of by the weight of K raises the
opposite end of G, releases H and gives freedom to B, which by reason of the
spring fork D immediately returns d and C, to a vertical position as at Fig. 4.
A suitable transmitter is placed upon A preferably in the position shewn by
the dotted outline thereof L, Figs. 1, and 3, and the instrument provided with
a push button of any suitable type for operating the signal circuit from the home
end to any one of the stations connected, and suitable lugs or their equivalents i
and placed upon A that the instrument may be suspended where desired.
Although as previously mentioned we prefer not to confine ourselves to the
employment of any of the well known systems of connecting the home instru-
ment with the circuits of the distant stations so as to be in signal or telephonic
communication with either at will, we have shewn in Fig. 2 how the lever G, by
means of contact points or the like, may, upon the removal of K, be arranged
to automatically close a telephonic or other circuit, and in like manner break the
same when K is returned to 9. Therefore, given that the contacts and circuits
have been suitably arranged and connected the manner of operation is as follows.
The signal being given to, or received from either of the distant stations, the
home operator would remove K, from g, and move C to the disc belonging to the
station to be communicated with when telephonic correspondence could be carried
on ad lib. The removal of K would operate the brake H, as before described, so
that C would remain where placed, and the movement of C imparting an identical
angular position to d, this by its larger diameter would operate upon, and push
open, or apart the forks of D, as in Fig 2, and shewn more particularly by Fig. 5.
At the termination of the correspondence the home operator would naturally hang K
again upon y, and this being in excess of the power of J, would depress g, and raise
the opposite end of G, releasing H, from B, as before described, the spring power
of D would immediately force d again into a vertical position and consequently C
upon the home disc e ready to receive the next signal from the same or any other
station in circuit.
By this means we are enabled to construct a compound telephone switch arranged
to be capable of operating with any number of distant stations by a suitable adjust-
inent of the contacts and circuits, and the electrical energy employed, and safely
rely upon the instrument being automatically returned to zero ready to receive a
signal from either station.
Having now particularly described and ascertained the nature of our said inven-
tion and in what manner the same is to be performed, we declare that what we
claim is.
1st. In an improved switch for telephone circuits, the apparatus herein described,

page_text: connected combined and operating in the manner set forth substantially as and for
the purposes herein specified, and shewn by the accompanying drawings.
2nd. In an improved switch for telephone circuits the construction and use of a
disc, wheel or other device B, carrying a pointer or contact maker C, and oblong
boss d, the latter operated by a vertical spring fork or tweezers D, the tension of
which tends to keep and C in a vertical position. The employment of a band H,
partly surrounding and acting as a brake for B, and connected to, and operated by
the movements of, a pivotted lever arm G, actuated by an adjustable spring J, when
the receiver K is removed from the hook, in combination with a switch board A,
carrying a suitable transmitter L, and bell or other signal F, and suitable press
button, for operating the distant signals, and provided with a crescent E, carrying
any number of metallic stud dises e e¹, clectrically connected to the line wires of a
corresponding number of distant stations, and provided with suitably arranged
internal contacts, connected combined and operating substantially as and for the
purposes hercin described and shewn by the appended drawings.
3rd. In an improved switch for telephone circuits, the manner of automatically
returning the contact maker C, to the home point or zero e¹ by the operation of the
disc, wheel or other device B, actuated by a spring fork D, operating the oblong
boss d, in conjunction with a pivotted lever arm G, and adjustable spring J, and
carrying or holding the receiver K, substantially as herein described and shewn and
for the purposes specified.
Ja of Santamban 1001
GEO. THOS. HYDE,
4, Moorfields, Fore Street, London, E.C., Agent for the Applicants.