IMPROVEMENTS IN AND APPERTAINING TO THE OBTAINING OF LIGHT BY MEANS OF ELECTRICITY, AND IN APPARATUS THEREFOR
Year: 1878

page_text: LETTERS PATENT to William Phillips Thompson, of 6, Lord Street, Liverpool,
in the County of Lancaster, Consulting Engineer and British and International
Patent Agent, for the Invention of "IMPROVEMENTS IN AND APPERTAINING
TO THE OBTAINING OF LIGHT BY MEANS OF ELECTRICITY, AND IN APPARATUS
THEREFOR." A communication from abroad by Monsieur Emile Reynier,
Engineer, of Paris, in the Republic of France.
PROVISIONAL SPECIFICATION left by the said William Phillips Thompson
at the Office of the Commissioners of Patents on the 17th June 1878.
WILLIAM PHILLIPS THOMPSON, of 6, Lord Street, Liverpool, in the County of
"IM-
Lancaster, Consulting Engineer and British and International Patent Agent.
PROVEMENTS IN AND APPERTAINING TO THE OBTAINING OF LIGHT BY MEANS Ов
ELECTRICITY, AND IN APPARATUS THEREFOR." (A communication from abroad by
Monsieur Emile Reynier, Engineer, of Paris, in the Republic of France.
.
This Invention is based upon a discovery of Mr. Reynier, that if the electric fluid
is caused to traverse a cylinder, prism, or piece of carbon from a lateral to a
terminal contact point, and in sufficient quantity to bring the said carbon to in-
candesence, a brilliant light is produced, and the carbon wears away at the point.
Numerous ways could be found for applying this fact or principle of science to
practical use, and it is for its application to electric lighting that this Invention is
designed. The plan of doing this that I at present prefer, is to take a long stick or
pencil of carbon; this is guided by an insulator near the lower part, and a pivot at
the top, this pivot by the weight of itself and its attachments, presses the stick of
carbon downwards. On the vertical attachment of this pivot I place a rack, on
which works a train of gearing of rapidly increasing speed, to a plate or disc of
carbon or other suitable refractory conducting material, upon the edge of which is
supported the pivot or end of the carbon stick. Some distance from the end of the
carbon stick, a platinum or other conductor is pressed against the said stick, and
the disc forms the other conductor.

page_text: The mode of action is as follows:-The electricity traversing the stick from the
lateral to the terminal conductor heats it to incandescence, giving forth a brilliant
light; at the same time the termination of the stick is slowly consumed. The
weighted pivot causes the stick to descend and make up for the loss, and as the
pivot and its attachments descend, the train of wheels are set in motion, and the
disc is rotated at a much greater speed than that of the descent of the stick, thus
giving a continually fresh surface to the point of the stick. At the same time the
stick acts as a break on the disc, and thus by friction regulates its own descent,
and consequently always presses with an even weight on the disc, and the contact
is thus continually kept up. The lateral contact of the platinum or other couductor
is easily kept up, as the bar simply slides past it, and the pressure of a spring is all
that is required to keep the contact constant.
SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said William Phillips Thompson in the Great Seal Patent Office on the
17th December 1878.
WILLIAM PHILLIPS THOMPSON, of 6, Lord Street, Liverpool, in the County of
Lancaster, Consulting Engineer and British and International Patent Agent.
"IM-
PROVEMENTS IN AND APPERTAINING TO THE OBTAINING OF LIGHT BY MEANS Of
ELECTRICITY, AND IN APPARATUS THEREFOR.' (A communication from abroad by
Monsieur Emile Reynier, Engineer, of Paris, in the Republic of France.)
The Invention rests upon the following discovery:-If a pencil of charcoal of any
convenient cross section c, Fig. 1, pressed with a terminal contact B, and touched
laterally by a contact 7, is traversed between these two contacts by an electric
current sufficiently intense, it becomes incandescent botween i and j, and is con-
sumed at its extremity ; more quickly than elsewhere. It gets thinner towards
the point, and tends to foreshorten itself. Consequently, the carbon c pressing con-
tinually in the direction of the arrow, advances gradually in proportion to its waste
slipping in the lateral contact 1, so as to abut without cessation on the terminal
contact B. This phenomenon is produced both when exposed to the air or in a
closed vase, but it is more brilliant in the open air because of the combustion of
the carbon.
Fig. 1 represents the carbon c vertical and progressing from top to bottom, but it
can be placed in any position. It is pressed by a weight or spring, or by any other
suitable medium of propulsion.
In order to make the lateral contact as sure as possible, it is preferably made
elastic, and of 1 to 3 or more conducting pieces, exercising upon the carbon pencil a
continuous and moderate pressure.
:
The Figures 2, 3, and 4, show examples of lateral clastic contact. In Figure 3, the,
two pieces and are moveable. In Figures 2, 3, and 4, the carbon c is pressed

page_text: between a fixed piece l, and an elastic piece . The pressure is obtained by springs,
by weights, or by other mechanical artifices. In any case, this pressure ought not
to be such that it can prevent the progression of the pencil c.
The carbons employed containing impurities, leave cinders which could accumulate
upon the terminal contact, and interfere with the electrical communication.
In order to obviate this inconvenience, I give to the terminal contact a rectilinear
movement, Fig. 2, or rotation, Figs. 3 and 4, and thus have a surface of contact
continually renewed, of which the parts already touched could, if necessary, be
automatically cleaned during the movement.
To obtain the displacement of the terminal contact, one can render its movement
dependent upon, and consequently a ratio of the rate of progression of the pencil o,
or have two independent motors, the one pressing on the pencil, the other actuating
the terminal contact. In fine, in the case of a terminal contact circular and move-
able about its axis, one can obtain its rotation in the following manner: The
incandescent pencil encountering the circular contact in a position not normal to
the centre, its pressure furnishes tangential force which causes the roller to turn
(contact B, Fig. 4.)
It would be impossible to describe all the arrangements for carrying out the
principle of this Invention, namely, electric light produced by incandescence with
terminal wear, but the specimen now to be described is one of the thousand forms
that could be taken, and is shown as a good example to explain more readily the
drift of the Invention, see Fig. 5. The stick of cylindrical or prismatic carbon c
rendered incandescent between i and j by the passage of the electric current, is
pressed constantly in the direction of the arrow by the weight of the metallic
bracket P, P, this heavy piece sliding between friction rollers G₁, G, G, G₁, mounted
in the vertical frame E.
The lateral contact is a circular piece of carbon or metal b oscillating upon a
little trunnion, and by the action of a weight m lying in i upon the pencil a little
below the metallic gland or socket which it traverses.
The terminal contact is a circular piece of carbon or metal B, moveable around
an axis T. The carbon c bears on the roller in a direction not normal to the axis,
and determines its direction in the direction indicated. Thus the descent of P, P,
in the same time that it produces the progression of the carbon, determines the
moveable of the terminal contact. Movement which ensures the efficacy of the
contact. In fine, the axis of the roller is mounted upon a joint or arm moveable
round O in such a manner that the pressure of the carbon c upon the roller B
determines the pressure of the arm F upon the shaft T, and produces upon this
shaft an action as of a brake. When the pencil weighs too little or does not weigh
upon the terminal contact, the heavy shaft acting without brake, urges with its
entire force the carbon to progress, until the extremity of the carbon comes to press
upon the terminal contact. If the motor continued then to press forward the
carbon as energetically, the latter would be broken at the incandescent part, but
the contact that it exercises upon the terminal contact puts a brake upon the
mechanism, until the pencil by its wear again permits the progression. Practically,
the alterations of motion and stoppage are nearly insensible, and the progression is
nearly continuous.
The wires coming from the source of electricity are fixed, the one in the insulated
terminal D, which communicates by the wire S with the insulated collar H, and
consequently with the terminal contact B; the other in the terminal D₂ which
communicates with the lateral contact ₁, and l₂, and with the mass of the apparatus.
In the foregoing Specification, I have endeavoured to keep as near as possible to
the actual words of the communication of the talented inventor, and in so doing,
have translated the French word contact by its English synonyme, whereas the word
pole or electrode would in some cases have been more appropriate. This remark
will however entirely prevent all chance of the description not being understood.
Having now described my Invention and the best mode known to me of carrying

page_text: it into effect, I wish it to be understood that what I believe to be new, and desiro
to protect under the herein-before in part recited Letters Patent is,--
İst. The manufacture of electric light by means of a rod or stick of carbon, or
other similar material with lateral electric contact, and with its point kept con-
tinually pressed against, and in contact with another conductor forming the other
pole or electrode of larger sectional area or surface at and around the point of
contact, whether it be a disc, flat or rounded surface roller, or other shape whatsoever,
and in such manner that the chief wearing away shall take place on the carbon or
composition rod, and at or near its point.
2nd. The apparatus for producing electric light and preventing the accumulation
of cinder consisting of a rod with lateral electric contact, with its point pressed
continually by means of a weight, spring, or other motive force against a roller or
other rolling or sliding surface forming the opposite pole or electrode, so that as the
pencil or rod gets used up, the said roller or its equivalent shall rub off the cinder,
and present fresh clean surfaces to the descending rod.
. 3rd. The electric lamp, substantially as herein described.
In witness whereof, I, the said William Phillips Thompson, have hereunto set
my hand and seal, this 14th day of December, in the year of our Lord One
- thousand eight hundred and seventy-eight.