Carbons for Electric Lamps.
Year: 1886

page_text: Carbons for Electric Lamps.
I, JOHN THOMAS LISTER, of Cleveland, in the county of Cuyahoga, State of Ohio,
United States of America Inventor do hereby declare the nature of this invention
and in what manner the same is to be perforined, to be particularly described and
ascertained in and by the following statement :—
My invention relates to improvements in the Art of Manufacturing Carbons.
The ordinary process of making carbons, or carbon points, may be briefly stated as
follows:
The composition being properly prepared by grinding and mixing the ingredients,
the person known as the moulder weighs it out on scales according to the size of the
carbon to be produced. From the scales the material or dust, as it is usually termed,..
is poured into the mould which mean-time has been heated sufficiently in a furnace
to melt the pitch contained in the dust and produce an agglutinated mass of proper
consistency to be moulded into the desired form and solidity. The mold is then
placed in the hydraulic press and subjected to a pressure of from three to five
hundred tons, after which it is removed from the press and the carbons taken fiom
the mold and laid away to cool. The cooling required at this stage of the proceedings
is such as will make the carbons firm enough to bear handling without sustaining
injury.
In the process of molding, a web unavoidably forms between the carbons of such
weight and strength that all the carbons in that series or impression are held firmly
together. Before anything further can be done it is necessary to break these webs
and reduce the carbons to separate pieces. This is done by striking the webs, one
after the other, with a metal plate or knife. The division of the carbons being
accomplished the seams are removed and the carbons pointed. By another process
the points are formed in the molds.
It will be apparent from this brief statement of the method of making carbon points
that it is exceedingly primitive and materially defective in several important
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page_text: particulars. In the first place the entire process, from the time the carbon dust is
placed in the scales till a marketable article is produced, except in the matter of
pressing, is performed by manual labor. No successful attempt, as far as I am aware,
has heretofore been made to introduce mechanical appliances to take the place of
human hands in any of the steps above enumerated with the trifling exceptions herein
acknowlodged. Now when it is remembered that carbon manufacture is carried on on
a large scale and involves the employing of hundreds of men in a single factory the
expensiveness of the present system will be appreciated.
But the old process is objectionable apart from the matter of costs. First, it is
impossible to distribute the material equally to all parts of the mold by pouring
directly from the scales, as is the common practice, for the reason that the material
becomes more or less packed in the center when it is emptied while it is light at
the sides and ends to which it is afterwards spread, thus producing carbons of unequal
density in themselves and of unequal weight compared with each other.
Second. The removal of the carbons from the mold while warm is objectionable
because the work can scarcely be done without inflicting more or less injury. The
practice is to lift the carbons bodily up at one end and while in that position to
introduce a thin metal plate on which they are removed to the cooling table where
the sheets or forms are placed one upon the other; but being warm and hence soft
and flexible they are exceedingly liable to become bent and therefore damaged if not
indeed rendered worthless by this change. Indeed one of the principal objects in
placing one layer of carbons upon another after removing them froin the mold is to
take out the crooks and bends produced by handling at this time, but this method of
straightening is only partially successful and the result is that many carbons are thus
irreparably injured.
Third. The web being broken by striking it with a metal plate, as above indicated,
leaves a ragged edge or seam which has to be removed by handling each carbon
separately and scraping the seam or grinding it down by means of an emery wheel, a
process that at best is very slow and results in frequent breaking of carbons. This
process is varied by forcing the carbon through an annular steel cutter, but the cutter
does not wholly remove the seams while it also breaks a number of points.
Fourth. The method of pointing carbons by grinding on an emery wheel is slow
and tedious, requiring much care to get the point exactly in the center. The exception
to this method is to form the point on the carbon in the mold.
Altogether the loss of carbons by bending, breaking, and other fatal injuries
amounts in the best regulated establishments to fully twenty-five per cent. of the whole
number originally placed in the molds, with a corresponding incidental loss of time
and labor expended in their manufacture.
By my process those several objections are almost wholly obviated, and new steps
are introduced and mechanisin employed whereby the manufacture of carbons is
greatly simplified, cheapened and improved.
Primarily the invention consists in improvements in the process of making carbons,
and, secondarily, in substituting machinery for hand work in carrying the process
into effect.
The improvements in the process consist, first, in the heating of the carbon dust
by placing it in the molds while they are cold and heating molds and dust
together.
Second. In the uniform distribution of the carbon dust in the molds so that
carbons of equal density throughout their length and of equal weight compared with
each other may be produced.
Third. In cutting the web close to the side of the carbon thus avoiding a seam or
rib and leaving the carbon smooth and round.
The improvement in the mechanism by which the process is carried out consists
in the construction of parts hereinafter fully described and particularly pointed out
in the claims.
In the drawings Fig. 1. is a plan view of the carbon apparatus in its entirety ;
Fig. 2 is a side elevation of the same; Fig. 3 is an enlarged plan view of the

page_text: revolving table showing the molds in position on its surface and the hydraulic
press beneath; Fig. 4 is an elevation in section on line 1, 1, Fig. 3 showing the
hydraulic press or ram and its connecting mechanism from the center of the table;
Fig. 5 is an elevation in section on line 2, 2 of Fig. 3 showing the ram in position to
operate on one of the molds; Fig. 6 is a horizontal section on line 3, 3 Fig. 4;
Fig. 7 is an isometric view of gear and ratchet for revolving the table carrying the
molds; Fig. 8 is a sectional view of the ratchet on line 4, 4 Fig. 5; Fig. 9 is a
perspective view of the valve mechanism for controlling the movements of the ram
through a rack on its side; Fig. 10 is a vertical section of the same; Fig. 11 shows
a carbon mold mounted on wheels with the cover and enclosing frame detached;
Fig. 12 is a side view of my automatic dust feeding device; Fig. 13 is a vertical
longitudinal section of the same; Fig. 14 is an enlarged transverse vertical section
thereof on line 5, 5 Fig. 12; Fig.414ª is a detail of the sliding cut offs; Fig. 15
is an end view of the reversing car and mold in transferring position taken on
line 6, 6 Fig. 2; Fig. 16 is an isometric view of a transferring car and its slotted
cover detached; Fig. 17 is a side elevation of the same with the cover on the car ;
Fig. 18 is a longitudinal section on line 7, 7 Fig. 19; Fig. 19 is a transverse section
on line 8, 8 Fig. 17 showing the cutters in position to sever the webs between the
sections; Fig. 20 is a side elevation of the pointing mechanism; Fig. 21 is an end
elevation showing the series of centers; Fig. 22 is an elevation of the opposite end;
and Fig. 23 is end view of a sheet of carbons as they appear after leaving the mold
and before severing the webs.
A represents the mold consisting of upper and lower sections a, a², and rectangular
enclosing frame a³ of the usual form and supported on flanged wheels a³.
B is a cylindrical receptacle for the carbon dust when suitably prepared to enter the
mold, and has at its end a feed spout b. Within the receptacle B is a revolving
screen D which practically fills the interior of the receptacle and is open at one end
to allow the feed spout to extend theroin and deliver the dust toward the center of the
screen. The screen is driven by power taken from any available source, a pulley on
its shaft being provided for that purpose, and is designed to sift the dust into the
conveying trough below. This trough is occupied by a conveyor or worm d run
by a pulley and belt from the screen shaft. The screen and conveyor not only
perform the functions here assigned to them but serve to thoroughly mix the carbon
material if this has not been well done before. Perfect mixing of the dust and the
pitch is highly essential to good work, and cannot be accomplished without much
painstaking labor. Any defects in this particular will therefore be remedied by the
screen and conveyor.
From the conveyor the material drops into the delivery spout E which has
partitions e corresponding to the carbon grooves in the mold A, and are designed to
distribute exact and equal quantities of the material uniformly to each separate
sub-division of the mold. Over the lower end of the delivery spout is arranged a
sleeve E' adapted to slide up and down on the spout and having partitions e¹ corre-
sponding to the partitions and serving to direct the material to its proper place in
the mold. The movements of sleeve E are automatic and may be traced as follows;
a shaft F supported in suitable bearings is connected with the hydraulic ram by a
rigid arm (Figs. 2 and 6) having a slot in its end and working over a pin on the
ram.
On the opposite end of the shaft is another rigid arm pivotally connected
with a yoke the arms of which are attached to trunious on the sides of the sleeve E'.
Transversely through the lower part of the sleeve E' and within its end walls is formed
an opening which corresponds to and is continued in the grooves in the guides e³
formed on the sleeve E. In these guides and opening, I place slides or cut offs G
one of which enters from each end or side of the sleeve and has its bearing in the
guide and opening. The shaft F has a third rigid arm and on one of the trunions f
is mounted a centrally pivoted lever . A link or rod connects arm with one
arm of the pivoted lever, and links connect said lever with the ends g of the
slides G. With the mechanism thus completed the operation of this part of the
machine is as follows; let us suppose the slides G to be withdrawn and the sleeve

page_text: down around the box of the mold. The mold having stopped beneath the delivery
spout just long enough to be filled, and this time is graduated to correspond exactly
with the movements of the turn table and the molds that have gone before, as will be
seen further on, the shaft F operates at the same time in the downward movement of
the ram to close the slides in against each other so as to cut off the feed and to raise
the sleeve to permit the mold or car to pass from beneath. Then at the proper time
another car is placed in position; the reverse movement of the shaft caused by the
upward movement of the ram, opens the slides till they have cleared the interior of
the sleeve and lowers the sleeve about the mold when the operation of filling is
repeated. This action is alternated while the machine is in operation, one mold being
filled while another is being pressed and so on indefinitely. To prevent the escape
of dust between the partitions e e¹ when they overlap deflectors are placed in the
upper partitions. It should have been mentioned that by the method of feeding and
distributing to the mold here adopted, and with the device for cutting off the supply,
exactly an equal quantity of material is fed to each mold, and no system of weighing
or measuring other than is thus provided is required.
I represents a track on which the cars travel in a circuit to and from the place of
filling. After being filled and covered, the cars or molds are directed to the
furnace K. Here they remain a sufficient length of time to be so heated as to give
the proper consistency to the carbon material preparatory to pressing. Thence they
are passed on to the turntable L which is provided with a series of short tracks 1, 1,
arranged to register with the respective ends of the track I. Suitable stops are
formed in the inner ends of the tracks 7 so as to place each car in the proper position
to pass into the press.
It is obvious that a track might be constructed to carry the molds directly to or
through the press, and that instead of using molds with wheels the mold might be
placed in a wheeled carriage or constructed to ride on rollers in the track or to slide
on the track; and that an endless chain or similar mechanism might be employed to
move the molds along.
M represents the hydraulic press or ram which may he of any well known
pattern, the press in itself forming no part of my invention. On the side of the
piston I secure a rack m which gears with a pinion m' on a shaft m². The shaft m²
has a segmental gear which meshes with a bevel wheel a on a vertical shaft N.
On the upper end of this shaft is a pinion n which engages with a gear on the
interior of the turn table L, and on its lower end, beneath the bevel wheel, is a pawl
and ratchet device n shown clearly in Figs. 7 and 8. The design of this mechanism
is to revolve the turn table L, and its operation is as follows; supposing a mold to
have been carried in position for pressing, the ram moves up and performs its work
but without turning the shaft N for the reason that the ratchet device keeps the hevel
wheel out of engagement with said shaft. But the ram or press having reached
the limit of its upward movement the induction valve is reversed and the ram descends
which instantly starts the gearing in the opposite direction, throws the ratchets into
engagement, turns the shaft N and the turn table till the segmental gear m³ is
exhausted when the turn table stops. The segmental gear is intended to be of such
range as is required to move up another car or mold to replace the one that has been
pressed, and to leave it exactly in its proper position for pressing. This of course
occurs while the ram is descending, and there is no movement of the table when it
ascents and presses the next succeeding mold.
In carrying out these operations it is desirable to have the hydraulic
press automatic
in its movements so that the action will be regular and uniform and the presence of
an attendant at the valves may be dispensed with. This I accomplish in the manner
following; referring to Figs. 9 and 10 represents the induction pipe, o¹ the pipe
leading to the hydraulic cylinder, and the eduction or discharge pipe. Extending
into the pipe o is a cylindrical valve P closely fitting said pipe and having a closed
outer end and an open inner end, and an annular opening in its side which registers
with both the induction and the eduction pipes o, o² alternately.
The valve P has a stem p projecting outward through packing in the head of

page_text: pipe o on which a gear wheel p¹ is loosely mounted and adapted to turn independently
of the said stem and valve. This wheel is provided with a curved slot p² about
midway between its axis and periphery. On the end of stem p is rigidly secured a
segmental plate p³ having a curved slot p* corresponding to slot p² in the genr
wheel p Between the segmental plate and the gear wheel is a weighted lever p
pivoted loosely on valve stem p and provided near its center with a pin p which
projects laterally on both sides of the lever into the slots pt and 2² of the segment
and
gear wheel respectively. The gear wheel meshes with a short rack on the
hydraulic piston by which it is operated.
It will be seen that the pipes o, o² are set at right angles to each other in the
pipe o¹, so that they are but a quarter turn apart. The valve P is therefore provided
with an opening p in its side which when given a quarter turn in either direction
will register with the induction and the eduction pipes alternately. I have therefore
arranged my valve mechanism in such manner that the valve will be automatically
thrown from one position to the other according as the hydraulic piston is at the
upper or the lower end of its stroke. This is accomplished by the weighted lever p²
dropping right or left from a vertical position by its own gravity within the limits of
the slot p² in the gear wheel. Thus for example suppose the lever to have been
raised from the left to a perpendicular position as shown in Fig. 9. The instant it
passes a perpendicular line it will fall to the right and carry the segmental plate p³
which is rigid on the stem of valve P, with it, reversing the valve from com-
munication with the eduction pipe as shown in Fig. 10 to the induction
pipe o. The instant this occurs the parts will be in the position shown in
dotted lines on the right in Fig. 9, the slot in wheel p¹ being behind the
seginental plate and exactly opposite the slot in said plate. Then the hydraulic
piston being at the bottom of its movement at once begins to ascend and in doing so
carries the gear wheel up on the right. This movement goes on till the lever lifted
by said wheel is again brought to a perpendicular position when it drops to the left
and reverses the valve to the eduction pipe. In this action one end of the pin p" of
the lever is caught in the slot p³ while the other moves freely in slot pt till it reaches
the upper end thereof. Meantime the segmental plate and valve remain unmoved
and the flow of fluid into the hydraulic cylinder goes on. But the instant the
weighted lever passes the perpendicular position it falls to the left, one of its arms
passing down in slot p while the other carries the segmental plate ps with the valve P
a quarter turn to the left when the change is complete.
After a mold has passed through the press it is carried around on the turn-table till
it reaches the discharge end of the track I where it is switched off and run down to
the reversing table Q This table practically forms a part of the track I but involves
a separate construction. As here shown the table is provided with trunions
centrally at each end which rest in hearings on cross bars between the rails, and
flanged guide ways along its track which serve to engage the hubs on the wheels
of the mold while the table with the mold therein is being reversed. A suitable
spring latch q² at the side of the table holds it steady when a mold is being taken on
or discharged. A mold being run in upon the table, the cover and rectangular
enclosing box are removed and the car shown in Fig. 16 placed thereon in reverse
position. The two cars are then locked together by latches 2 at the side when they
are in readiness to be bodily inverted and lowered to track S.
This track has a table corresponding in position to the table and is immediately
beneath it. It is supported on strong springs at its corners which when permitted to
exert their force carry the section or table up in contact with the inverted car R
which by the change is now on the under side. The latches 3 are then released and
the car R is lowered to the end of the track S and switched off. The other car is
restored to the track I and started around to be re-filled with carbon dust and passes
through the process hereinbefore described.
It will be observed that the car R has a platform provided with grooves corre-
sponding exactly to those in the mold in size and unumber. In the change from the
upper to the lower track the carbons are transferred to this car. Up to this time all.

page_text: the carbons remain in the sheet or form in which they were pressed and are connected
by webs. It is necessary now before proceeding further with the manufacture to
divest the carbons of the webs and so dress them that no seams or ribs will be left
along the side where the webs were connected. To accomplish this object I form
slots between the grooves in the car R which extend through the platform, and
corresponding slots or cuts are made in the cover of the car shown in Figs. 16
and 19. This car is further provided with projections at its side which are adapted
to enter guides T placed at the side of the track as shown in Fig. 19. Immediately
above the center of the guides T is arranged a shaft, V carrying a series of discs or
cutters designed to enter the slots in the car R and sever the carbon webs. This
shaft is driven by power taken from any available source, and the discs are preferably
made with square edges and of such thickness that they will cut the web close to the
carbon, thus leaving the carbon perfectly round after the web is removed.
The operation of this part of the machine is as follows: the car R being loaded with
carbons and provided with its slotted cover is driven along the track through the
guides T and beneath the discs » which are revolving at a high speed. The guides
serve to accurately center cach car as it comes along and bring the slots in perfect
alignment with the discs, and the car being driven with sufficient impetus to clear the
guides and the cutters. The severing of the webs is the work of but an instant. It
is of course understood that as yet the carbons are warm and the material easily worked.
After leaving the revolving discs by which they have been separated into single
points or carbons they are passed along a continuation of the same track to the
mechanism by which the pointing is accomplished and which requires only an instant
to complete the points. This operation is performed by means of a number of
triangular projections revolving eccentrically upon short steel shafts journaled upon
a stationary frame or standard placed transversely across the track each shaft having
its center alternately opposite the center of one of the carbons still held closely
between the traveling car R and its cover. The cutters are so beveled upon their
inuer faces as to correspond to the desired bevel of the finished carbon point and
having sharp edges quickly remove the material to the required depth. The shafts
are connected by gears behind the frame and driven by the band wheel. This
mechanism is shown fully in Figs. 20, 21 and 22 where X represents the standard,
Y the eccentric points or cutters, y the gears and y¹ the band wheel. In operation
the carbons are so placed in car R as to leave a portion of the carbons exposed and
projecting from the car which is advanced toward the revolving cutters until they
nave cut to the desired depth in the finished points, when the car may be switched off
and another take its place.
In this manner a number of carbons may be pointed at once while the material is
still soft without bending or injuring them in any way.
Fig. 23 represents a card or sheet of carbons Z after leaving the mold and connected
by the webs z ready to pass through the separating discs.
The entire proceeding from the time the molds are filled with the dust till the final
step in the process is reached occupies but comparatively few minutes, and there is no
pause or break in the work except such as is provided for in the general plan and
needed to make the changes which the process involves. It will also be observed that
the carbons are constantly in action and at all times are either supported in or travel
over surfaces which protect them their entire length and prevent the bending or
warping to which they were liable under the old process.
Having thus described my invention what I consider now and desire to secure by
Letters Patent is ;
1. The method of separating carbons consisting, first, in removing the carbons from
the mold while in a warm or pliable state to a channelled and grooved platform, and
then passing the platform with the carbons beneath the cutters to cut the webs,
substantially as set forth.
2. The method of pointing carbons by forming the point while the carbon is warm
and pliable, substantially as set forth.

page_text: 3. The method of pointing carbons by taking the carbon while in a warin and
pliable state and exposing its end to the point forming mechanism, substantially as
set forth.
4. In a carbon machine, a hydraulic press, a turn table arranged to pass through
the press, and a track the ends of which terminate at the turn table, substantially as
set forth.
5. In a carbon machine a track, a turn table connecting the ends of said track, a
hydraulic press and a mold, substantially as set forth.
6. In a carbon machine, a hydraulic press, a track, a mold with wheels and a
stationary device for filling the mold, substantially as set forth.
7. In a carbon machine provided with a mold, a device for feeding carbon dust to the
mold and a furnace for heating the dust and mold together, substantially as set forth.
S. In a carbon machine a hydraulic press, a track, and a filling device and furnace
arranged along said track, substantially as set forth.
9. In a carbon machine, a hydraulic press or ram, a turn table and mechanism
connecting the press and turn table, whereby the table is turned by the movements of
the ram, substantially as set forth.
10. A carbon machine comprising a press, a track and a mold adapted to move on
the track, in combination with a carbon dust feeding device, arranged to fill the mold
and mechanisin whereby the feeding device is separated when the press moves upward
and downward, substantially as set forth.
11. In a carbon machine a press, a curved track, a mold to travel on the track, a
device for feeding the dust to the mold and a shaft and gearing connected with the
press and the feeding device, whereby the press is made to operate the feeding device,
substantially as set forth.
12. In a carbon machine a device for feeding dust to the mold, a press and a shaft
having an arm at one end connected with the press, and arms and cut off mechanism
at the other end for controlling the flow of dust, substantially as set forth.
13. A carbon machine having a press, tracks leading to and from the press, and
a mold to travel on the tracks, in combination with a carbon dust feeding device
provided with a series of channels for filling the mold and mechanism for operating
the feeding device, substantially as set forth.
14. In a carbou machine having a press, a track, and a mold in combination with a
carbon dust feeding device provided with grooves and channels and automatic cut offs
in the channels, substantially as set forth.
15. A carbon dust feeding device having a series of channels, a revolving screen
and worm above said channels, and cut offs in said channels, in combination with a
carbon mold, substantially as set forth.
16. In a carbon machine a carbon dust feeding device provided with a channelled
sleeve, a channelled guide above the sleeve, and cut off mechanism, in combination
with a mold, substantially as set forth.
17. In a carbon machine a carbon dust feeding device provided with a channelled
sleeve, a carbon mold and mechanism for adjusting the sleeve to and from the mold,
substantially as set forth.
18. In a carbon machine, a press, a turn table arranged to revolve through said
press and gearing connecting the press and table and constructed to revolve the table
when the press descends, substantially as set forth.
19. In a carbon machine a hydraulic press or ram, a valve located in the fluid pipe
and mechanism connecting the ram and valve, whereby the valve is automatically
operated by the ram, substantially as set forth.
20. In a carbon machine a hydraulic press or ram, induction and eduction fluid
pipes, a valve connected with said pipes and mechanism connecting said valve with
the ram for automatically operating the valve when the ram reaches the limit of its
movement in either direction, substantially as set forth.
21. In a carbon machine a hydraulic press or ram, fluid induction and eduction
pipes, a rotary valve adapted to said pipes and reversing mechanism connected with
said valve and operated from the hydraulic ram, substantially as set forth.

page_text: 22. In a carbon machine a hydraulic press or ran provided with a rack, fluid induc-
tion and eduction pipes, a valve adapted to register with either pipe alternately and
provided with a stom carrying a gear wheel, a segment, and a weighted lever, all
combined, substantially as set forth.
23. In a carbon machine an upper car track having a section converted into a
reversing table and a lower track in line with said section, substantially as set forth.
24. In a carbon nmchine provided with a mold on wheels, two car tracks one above
the other and a reversing device between them whereby the carbons are transferred
from the mold to a receptacle on the lower track, substantially as set forth.
25. In a carbon machine an upper track and a mold, in combination with a lower
track carrying a car, and a reversing device between the tracks, whereby the carbons
are transferred from the mold to the car, substantially as set forth.
26. In a carbon machine à car having grooves to hold the carbons and a grooved
cover having ends which project over the ends of the car and enclose the same,
substantially as set forth.
27. In a carbon machine a platform having grooves for the carbons and slots
longitudinally between the grooves, substantially as set forth.
28. In a carbon machine a car provided with grooves and slots running between
the grooves and guide projections at its sides, substantially as set forth.
29. In a carbon machine a car provided with projections on its sides and a track
having guides in which the projections move to center the car, substantially as set
forth.
30. In a carbon machine a platform provided with grooves and slots and a series of
cutters arranged to enter the grooves, substantially as set forth.
31. In a carbon machine a shaft carrying a series of cutters and a car having a
grooved platform with slots between the grooves, substantially as set forth.
32. In a carbon machine a cutting device so constructed so as to form a bevel point
on a carbon, substantially as set forth.
33. In a carbon machine a series of cutters arranged to operate together and
provided with cutting edges whereby the points are formed on the carbons, substantially
as set forth.
34. In a carbon machine a point forming cutter in combination with a device for
holding the end of the carbon in contact with said cutter, substantially as set forth.
35. The process of making carbons consisting of pressing the carbons in molds,
and then while they are still warm and pliable severing the webs and forming the
points, substantially as set forth.
36. In a machine for making carbons, a press, a track leading to and from the press,
and a mold constructed to move along the track, substantially as set forth.
37. In a carbon machine, a press, a track, a furnace arranged in the line of the
track, and à mold adapted to travel on the track and pass through the furnace,
substantially as set forth.
38. In a carbon machine a hydraulic press, molds for the carbons and mechanismi
on which the molds are conveyed to and from the press, substantially as set forth.