IMPROVEMENTS IN AND APPERTAINING TO ELECTRODES OR CONTACTS FOR TELEGRAPHIC OR OTHER ELECTRICAL INSTRUMENTS
Year: 1882

page_text: LETTERS PATENT to Frederic Des Voeux, of the Office for Patents, 32,
Southampton Buildings, in the County of Middlesex, for an Invention of
"IMPROVEMENTS IN AND APPERTAINING TO ELECTRODES OR CONTACTS FOR
TELEGRAPHIC OR OTHER ELECTRICAL INSTRUMENTS." A communication from
abroad by George Cumming and Clara Maria Brinkerhoff, both of the City,
PROVISIONAL SPECIFICATION left by the said Frederic Des Voeux at the
Office of the Commissioners of Patents on the 23rd February 1882.
FREDERIC DES Vœux of the Office for Patents, 32 Southampton Buildings, in
the County of Middlesex. IMPROVEMENTS IN AND APPERTAINING TO ELECTRODES
OR CONTACTS FOR TELEGRAPHIC OR OTHER ELECTRICAL INSTRUMENTS. (A com-
munication from abroad by George Cumming and Clara Maria Brinkerhoff both of
the City County and State of New York, United States of America.)
Telegraph keys, relays, pole changers, and other electrical instruments are usually
constructed with a lever or armature lever mounted on trunnions or otherwise held
in place and forming a hammer which impinges upon a stationary anvil whereby
the electrical connection is made or broken.
Heretofore the contact between two electrical poles of telegraph instruments has
been made either by metal points or ends of wires set square or by a point coming
in contact with the side of the margin of a disc's face.
The first method is objectionable because by reason of oxidation or fusion or
by dust collecting between the electrodes, only imperfect electrical connection can
be obtained and also because owing to the adhering of the points or so called
"sticking" rapid transmission is impossible. The second method is also objection-
able, because it only partially remedies the same difficulty of "sticking" owing to the
fact that but one of the contact points is adjustable, while the other point of contact
.
•

page_text: being a flat surface forms a large surface for adhesion of the poles, so that perfect
transmission with any reasonable degree of rapidity is impossible. This Invention
relates to improved electrodes for electrical instruments of all kinds, such as keys,
relays, sounders, pole-changers, fire and burglar alarms, annunciators, electric clocks,
and the like, whereby in place a surface contact a peripheral contact of the smallest
possible kind is obtained, and the Invention consists in making both electrodes or
contact-points adjustable and in the shape of discs, the axes of which are either
parallel or arranged at right angles to each other and the discs being provided with
platinum rims or tyres of round, triangular, cone-shaped, or other cross section
whereby a perfect electrical connection is ensured and at the same time the
smallest possible surface of actual contact is obtained.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by the
said Frederic Des Voeux in the Great Seal Patent Office on the 11th August
1882.
FREDERIC DES VEUX, of the Office for Patents, 32 Southampton Buildings, in
the County of Middlesex. IMPROVEMENTS IN AND APPERTAINING TO ELECTRODES
OR CONTACTS FOR TELEGRAPHIC OR OTHER ELECTRICAL INSTRUMENTS. (A com-
munication from abroad by George Cumming and Clara Maria Brinkerhoff both of
the City County and State of New York United States of America.)
Telegraph keys relays pole-changers and other electrical instruments are usually
constructed with a lever or armature-lever mounted on trunnions or otherwise held
in place and forming a hammer which impinges upon a stationary anvil whereby
the electrical connection is made or broken.
Heretofore the contact between two electrical poles of telegraph instruments has
been made either by metal points or ends of wires set square or by a point coming
in contact with the side or the margin of the face of a disc. The first method is
objectionable because by reason of oxidation or fusion or by dust collecting between
the electrodes only imperfect electrical connection can be obtained and also because
owing to the adhering of the points or so-called "sticking" rapid transmission is
impossible. The second method is also objectionable because it only partially
remedies the same difficulty of sticking owing to the fact that but one of the
contact points is adjustable while the other point of contact being a flat surface
forms a large surface for adhesion of the poles so that perfect transmission with any
reasonable degree of rapidity is impossible.
This Invention relates to improved electrodes for electrical instruments of
all kinds such as keys relays sounders pole-changers fire and burglar alarms
annunciators, electric clocks and the like whereby in place of a surface-contact a
peripheral-contact of the smallest possible kind is obtained and the Invention
consists in making both electrodes or contact-points adjustable and in the shape of
discs the axes of which are either parallel or arranged at right angles to each other
and the discs being provided with platinum or like metal rims or tyres of round
triangular cone-shaped or other cross-section whereby a perfect electrical con-
nection is ensured and at the same time the smallest possible surface of actual
contact is obtained.
In the accompanying Drawings Fig. 1 represents a side elevation of a telegraph
key constructed with the improved electrodes.
Figs. 2 and 3 are enlarged sections of the same.
Figs. 4. 5. 6. and 7 shew different forms of constructing the discs and their tires
and
Fig. 8 is a side elevation of a pole-changer with the improved electrodes.
Similar letters of reference indicate corresponding parts.
A A¹ represent two metal wheels or discs which are used as the two electrodes or
contact points, the peripheries of which are preferably placed at right angles to
each other, as shown in Fig. 1 applied to a telegraph key, or they may be arranged
in the same vertical plane, as desired. The discs are applied respectively to the
arch of the lever or hammer L and to the insulated standard or anvil B connected
with the base directly underneath and they are held in place by shafts or pivots
which are permanently attached to the centre of each disc and provided with set-
screws or jam-nuts working on the same. The discs A A' move freely when
required in their bearings slots grooves or holes of sufficient size being provided
for this purpose. In relays and other electrical instruments working with a
battery in connection with a key or other circuit breaking apparatus the action of

page_text: the disc electrodes is the same as in the key with only such changes as are rendered
necessary by the form of the instrument. In the double-current key or in pole-
changers two sets of discs are arranged one at each side of the key or armature
lever as shown in Fig. 8 so as to send at each vibration a reversed current over
the line.
The action of the device is as follows:-By pressure on the button of the key
connection is made between the two electrical poles of the key by the two discs A A¹
touching one another at their peripheries on a line vertical to the axis of each
disc. In relays or other instruments working with a battery in connection with a
circuit-breaking-apparatus the same action is effected by means of an electro-
magnet which is charged by the closing of the key. In this case the current from
the battery passes through the coils of the electro-magnet which then attracts the
armatures. When the key is opened the current is broken and the armature is
released in the usual manner. The opening and closing of the circuit causes the
vibration of the armature-lever and makes or breaks connection on the peripheries
of the wheels or discs which are held in place by suitable contrivances.
The contact discs are provided with rims or tyres of densely drawn platinum (or
other suitable metal) wire which tyres are well secured into the grooved peripheries
of the discs. The body of the discs is made of brass or other conducting metal.
The lower disc A¹ is shewn as made adjustable on the standard B by a set-screw b.
The upper disc A is shewn pivoted to the lever, and adjusted by the set-screw d.
e is a set-screw with lock-nut for adjusting the spring and f is a screw with lock-
nut for regulating the play of the lever which is hung on the trunnions g. The
cross-section of the rims or tires a may be (as before mentioned) of circular semi-
circular triangular conical or other shape.
Fig. 4 shews a round wire which is pressed welded or soldered into a groove in
the periphery of the disc while in Fig. 5 a triangular wire is shewn in Fig. 6 a
semi-circular wire let into a groove and in Fig. 7 a thin plate which is inserted
between two plates forming the disc. By this means the cost of the electrodes is
greatly lessened and a knife-blade needle-point or cone-shaped contact obtained.
One or both discs may be made entirely of platinum or like metal if desired.
The essential feature of the Invention is the reduction of the area of contact to the
smallest space possible so as to prevent sticking of the contact points and admit
rapid and perfect connection of the poles.
Having now described the nature of the said Invention as communicated to
me from abroad and in what manner the same is to be performed I would have it
understood that what I desire to secure under Letters Patent on behalf of the said
George Cumming and the said Clara Maria, Brinkerhoff is
Firstly: Constructing electrodes for electrical instruments in the form of metal
wheels or discs in such manner as to make peripheral contact as described.
Secondly As an improvement in electrodes for electrical instruments the con-
struction of discs or wheels having platinum or like metal rims or tyres of suitable
cross-section connected to the periphery of the discs as described.
In witness whereof I the said Frederic Des Voeux have hereunto set my
hand and seal this Fourth day of August in the year of our Lord One
thousand eight hundred and eighty two.