Improvements in the Process of Electro-plating, and Apparatus therefor.
Year: 1894

page_text: .Date of Application, 17th July, 1894-Accepted, 18th Aug., 1894
COMPLETE SPECIFICATION.
Improvements in the Process of Electro-plating, and Apparatus
therefor.
A communication by CLARENCE MORSE BARBER, of 423, Sibley Street, Cleveland
in the County of Cuyahoga, and State of Ohio, United States of America,
Mechanical and Electrical Engineer.
1, WILLIAM PHILLIPS THOMPSON, F.C.S., M.I.M.E., of The Agency for
Foreign Patent Solicitors, 6, Lord Street, Liverpool, and 6, Bank Street,
Manchester, both in the County of Lancaster and 323 High Holborn in the
County of Middlesex, Civil Engineer, 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:-
This invention relates to process of electro-plating and to apparatus for carrying
ou, automatically and continuously, the operation of electro-plating. The object of the
invention is to cheapen the cost of the electro-plating process and to ensure a more
uniform product than is at present obtained.
Broadly stated, the invention consists primarily in automatically conducting by
mechanical means the entire series of operations connected with the electro-plating
of articles, and, secondarily, in the combination and arrangement of co-acting
mechanism for feeding, conveying, plating, washing, drying and delivering the
articles to be plated. Although it is applicable to a great variety of articles, such
as bolt-heads, stove knobs, carriage and harness trimmings, etcetera, this invention
has special reference to the electro-plating of arc-light carbons, and for convenience
will be described as arranged for the plating of such carbons, it being understood
that it is not limited thereto.
In the annexed drawing,
Figure 1 represents, in side elevation, an apparatus constructed according to this
invention, as arranged for the electro-plating of arc-light carbons, the centre being
broken away on account of the length of-the apparatus ;
Figure 2 is a plan view of the apparatus shown in Figure 1 ;
Figures 3 and 4 are end elevations of the apparatus; Figure 3 showing the end
of the apparatus at which the carbons are fed in, hence called the "head end," and
Figure 4, the opposite or "foot end";
Figure 5 is a detail showing, partly in elevation and partly in section, the
construction and arrangement of the plungers and grooves of the feed drum;
Figure 6 shows, in end elevation, a portion of the feed-drum and the ends of the
feeding plungers;
Figure 7 is a detail showing in plan view and partial section the mechanism
(shown in elevation in Figure 3) for opening the clamping holders to receive and
discharge the articles to be plated;
Figure 8 is a transverse vertical section through a plating tank showing the
electrical connection; and
Figure 9 shows the method of drying the plated articles by means of a blast of--
air directed upon them.
In general terms the apparatus consists of an endless conveyor or carrier having
a series of clamping holders secured thereto, each of which is adapted to receive
from the feeding mechanism a single carbon rod or other article, and is provided
with means for making electrical connection with the circuit through the plating
tank in any suitable way. The carrier is arranged, by means of suitable sprocket
gear and guide wheels, to traverse past the feed drum in a line tangential to the

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periphery of the same, then over a series of vats or tanks 'in such manner as to
carry the carbons or other articles held by the clamps through the tanks, serially,
first through a tank or tanks designated as the cleaning or wetting tank or tanks, in
which they are treated to a suitable bath or baths to remove any grease, oil or
dirt that may have got upon them and to leave the surface of the carbons clean
and wet when they enter the plating tanks, so as to prevent the formation of air
bubbles upon their surface, and the absorption of fluid by the carbons while in
the plating tank. From the wetting tank the carbons are carried in the same
way through one or more plating tanks, then through a washing tank or tanks,
and through a drying chamber or space and to the point of discharge.
In the drawing A represents the endless carrier, a the clamping holders secured
thereto, B is the feed drum by which the carbons are continuously fed from the
hopper B' and supplied singly to the traversing holders a a. C C' are a pair of vertical
plates between which the holders a pass, and which are set so far apart that, in
passing between them, the clamping jaws of the holders a¹ are opened to receive
the carbons, as hereinafter more particularly described.
D D D D D, etcetera, are sprocket wheels, by means of which the carrier A
is moved and guided; d d d are guide wheels or idlers, by passing over which the
carrier is caused to raise the carbons out of one tank and pass them into another.
Power is applied by belt or gear to the shaft of one of the sprocket wheels, as seen
at D in Figure 1, and one or more of the sprocket wheels is provided with
adjustable bearings, as seen at D' in Figure 1, whereby any slack in the carrier
may be taken up. A suitable frame-work, as shown in the drawing, supports the
various parts. E represents the cleaning or wetting tank, F F the plating tanks,
and G G the washing tanks. H represents a drying chamber, I l¹ are two
plates, similar to C C₁, arranged to open the holders a to discharge the carbons
at any desired point.
K2 represents a table or shelf, box or other suitable receptacle upon or into
which the carbons are discharged, and from which they are taken
away in any
preferred manner. L L' represent respectively the positive and negative sides
of the electrical circuit through the plating tanks, 1 represents the anodes,
the contact piece attached to each of the clamps a for making electrical
connection with the circuit. The electrical connection is made by a sliding or
moving contact between the contact pieces 12 and a contact piece extending
along and above the plating tank and in electrical connection with the negative
side of the circuit. By this construction, the articles carried by the holders a
are in circuit only while in the plating tanks, the circuit being of course broken
for each carbon as it begins to rise out of the tank when the carrier passes up
over one of the guide wheels d, and made again as it descends into the next
plating tank.
The construction and operation of the various parts of the apparatus will now be
more particularly described.
The feeding apparatus consists of a rotating drum B, the periphery of which is
longitudinally grooved and forms a part or all of the bottom of the hopper B* in
which the carbons to be plated are placed in large quantity, and from which they
feed singly in the following manner :-
The grooves B³ in the feed-drum are each of a depth and width to receive one
carbon, and as the hopper is made equal in width to the length of the carbons, the
latter must lie parallel with the grooves B³, into each of which, as it comes under
the hopper, a single carbon falls and is carried forward. The grooves B' extend
the entire length of the drum B, which is longer than the width of the hopper, and
at the "head-end" of the drum there is located thereon, in line with each of the
grooves B, a casing b in which a plunger is fitted and adapted to slide in the
groove B with which it is in engagement. A spring & in the casing keeps
the plunger normally withdrawn from the groove B³ in which it plays, or enough
so to clear the opening of the. hopper, and with the outer end of the plunger
protruding from the "head-end" of the casing, as shown in Figure 5. To feed

page_text: the carbons from the groove B³, a cam O is employed, which is curved to
correspond with a short arc of the periphery of the feeding drum, and is located so
as to engage the outer ends of the plungers as they approach, touch and recede
from the vertical plane tangent to the feed-drum which contains the line of move-
ment of the holders a. As the plungers are successively brought by the rotation of
the drum B in contact with the cam O, they ride up the incline and are forced further
into the grooves B³, each pushing before it the carbon in the groove in which it
dies, and causing the carbon to project fro'n the other end of the groove, as shown
in Figure 5, in which to represents the carbon. As the plungers pass over the
maximum point of cam O and are carried past the same, the springs b² withdraw
the plunger and leave the groove clear to receive another carbon, and so on.
continuously.
The carrying apparatus consists of the endless sprocket belt A constructed as
follows:-
Two sprocket chains rr are secured to the ends of a series of bars S S S, to
the centre of which are secured the holders a, preferably one on each bar, and
insulated from the bar unless the latter is itself a non-conductor of electricity.
The holders of course placed in correct alignment along the carrier, and project so far
therefrom as to immerse the articles carried by them to the desired depth in the various
baths.
A very efficient form of holder is shown in Figure 7, and consists of a fixed
jaw a¹ having a movable jaw a pivoted thereto, and normally held closed against
the fixed jaw by a spring p acting against a rearward extension a³ on the pivoted
jaw a'. A stem from the fixed jaw passes through the bar S, which is preferably
formed of non-conducting material, and upon this stem, on the opposite side of
the bar, is secured the contact piece, all of which are clearly shown in
Figures 7 and 8.
The manner in which the carrier A is moved by the sprocket wheels is clearly
shown in Figure 1.
The carrier is charged in the following manner :-
The carrier, as shown in Figures 1, 3 and 5, is caused to pass the drum B in such
manner that the holders move in a plane tangential to the periphery of the drum
and parallel to the end of the drum, and so far from the foot-end of the drum that
the holders a will pass close to the same without quite touching it. The drum B is
so geared from its driving mechanism that its periphery moves at the same speed as
the carrier A, and the holders a the grooves B are equally spaced. The plates C CI
are adjusted one on each side of the path traversed by the holders a, and in a
plane transverse to the axis of the feed-drum, extending each way in a vertical
direction from the point where the path of said holders is tangent to the periphery
of the drum.
The plate C has an inclined cam-shaped edge, while the edge of C¹ is straight
and set parallel with and contiguous to the path traversed by the holders a, and on
the side occupied by the fixed jaw a'. Plate C is set so far from C¹ that, as the
holders a pass between the plates, the fixed jaw a' will ride on the straight edge
of C¹ as a guide, while the extension a' of the pivoted jaw a' will ride upon the
cam-shaped edge of C, and thus be caused to open the jaw a', the widest opening of
the jaw occurring at the narrowest part of the passage between the two plates CC',
which is located at or just above the point where the path of the holder intersects
the plane of rotation of the grooves B', and is continued of the same width for a
space sufficient to allow the carbon to be fully thrust into the holder by the plunger
in that groove, which occurs opposite to the maximum point of the cam C, and at
about the point where the path of the holders is exactly tangent to that of the
grooves B, after which the cam edge of the plate C rapidly recedes, allowing the
holder to close quickly upon the carbon.
The result of this construction is that, as the holders enter the space between
the plates C C above the point at which the cam O begins to act, they are opened
before the carbons in the groove of the feed drum begin to move, and cone into
line with the grooves B³, just at the time when the carbon therein begins to

page_text: protrude therefrom under the action of the plunger 6' and cam O, and as the
carrier A and drum B move at the same speed, the carbon is thrust into the open
jaws of the clamp and moves with the latter until it passes below the cam edge of
plate C, when the jaws will have closed upon the carbon, and it is held by the
clamp and carried out of the groove in which it lay by following the tangential path
of the carrier as the drum rotates away from it.
The tanks are made of a depth a little greater than the length of the carbon and
as long as required. It is preferred to form the plating tanks of metal sides f
supported by suitable framework; the anodes 1 rest on metal blocks, placed in
the bottom of the tank, and are secured to the top by clamps and hooks f*, which
engage the sides or framework of the tank, as shown in Figure 8.
The electrical connection is made by connecting the anodes, or preferably the
metal sides or lining of the plating tanks, with the positive pole of a suitable source
of electrical energy, such as a dynamo, while the negative pole may be connected
to a metallic bar or contact piece m, extending the length of the plating tank and
so located as to be engaged in sliding contact with the contact pieces as they
successively pass along. A metal block 9 is secured to the metal side or lining of
the tank, into which a metal plug t is fitted and connected to the positive
conductor L, while an insulated or non-conducting handle t' may be fixed to the
plug t.
When, as is preferred, a number of plating tanks is employed, each tank is
provided with a shunt circuit and switch whereby the electric current may be
shunted from one tank around the next tank and to the one beyond, in the common
method well known to electricians. The purpose of this is to enable any one of the
tanks to be removed or cut out of circuit without interrupting in any respect the
continuity of operation of the whole apparatus.
The drying apparatus consists preferably of an elevated chamber H through
which the carrier A is caused to pass, and which chamber may be either warmed or
supplied with an air blast as preferred. The carbons may be dried by a blast of
dry or warm air directed upon them without being in a chamber, or spontaneously
without either, and the invention is not limited to the employment of an enclosed
chamber or of an air blast for drying them.
In case an air blast is used, the arrangement shown in Figure 9 is suitable, the
blower X being placed in position to direct a blast of air along the path traversed
by the carbons after leaving the washing tank.
The discharging apparatus consists of two plates I I¹ similar to C C¹ and
operating in the same way. The holders being caused to pass between the
plates are opened as previously described, and as the plates I I¹ are arranged
to open the holders only when the carbons have commenced to descend as the
carrier passes around sprocket wheel D³, and as are below the centre thereof as seen
in Figure 1, the carbons drop upon the inclined trough K and slide down the same
to the table K³, or any receptacle provided to receive them. The empty holders
are then carried by passing the carrier A over the sprocket wheels D³, aligned
with D, past. the drum B, and refilled as above described; and thus the operation
is continued without interruption, the only attention required being to keep the
hopper B³ filled, the anodes and baths in proper condition, and the finished carbons
removed, all of which is easily accomplished without interfering in the slightest
degree with the continuous operation of the apparatus.
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed, as communicated to me by
my foreign correspondent, I declare that what I claim is :-
1. The process of electro-plating which consists in passing the articles to be
plated by a continuous movement through a succession of plating baths, in each of
which the article receives an increment of deposit, then washing and drying the
plated articles without interrupting their motion, substantially as described.
2. The process of electro-plating which consists in passing the articles to be

page_text: plated by a continuous movement through a cleaning or wetting bath, then through
a succession of plating baths in each of which the article receives an increment of
deposit, then washing and drying the plated articles without interrupting their
motion, substantially as described.
3. The process of continuously and automatically electro-plating articles which
consists in passing them by a continuous movement successively through the proper
cleaning plating and washing baths, arranged in their proper order, causing the
articles to forin part of the electrical circuit while in the plating bath, and drying
them while in motion after leaving the washing bath by means of a blast of air
directed upon them, substantially as described.
4. The continuous and automatic process of electro-plating which consists in
attaching the articles to be plated to an endless carrier, causing said carrier to pass.
over a series of tanks containing the necessary cleaning, plating and washing baths.
arranged in their proper order and to immerse the articles in the several baths
successively, causing the articles to form part of the electrical circuit while in the
plating bath, drying the plated articles while still upon the carrier, and continuously
removing the finished articles from the carrier and replacing them with untreated.
ones, substantially as described.
5. In electro-plating apparatus the combination of a series of tanks containing
respectively the proper cleaning, plating and washing baths, arranged in proper
order, an endless carrier adapted to carry the articles to be plated and arranged to
traverse over said tanks successively, an electrical circuit in which the plating bath
is included, and means for connecting the articles into said circuit while in the
plating bath, substantially as described.
6. In electro-plating apparatus the combination of a series of tanks containing
respectively the proper cleaning, plating and washing baths arranged in proper
order, an endless carrier adapted to carry the articles to be plated and arranged to
traverse over said tanks successively, an electrical circuit in which the plating
baths are connected, means for connecting the articles into said circuit while in the
plating baths, aud a shunt circuit connection to each of the plating baths whereby
any one or more of said plating baths may be cut out of circuit, substantially as
described.
7. In electro-plating apparatus the combination, with a series of tanks, of an
endless carrier arranged to traverse over said tanks successively, holders attached
to said carrier and adapted to hold the articles to be plated and to immerse them in
the baths contained in said tanks, an electrical circuit with the positive pole of
which the plating baths are connected and with the negative pole of which the
holders make connection while passing over the plating baths and thereby put said
articles in circuit while in the plating baths, and means for guiding said carrier so
as to cause the same to pass the articles carried by said holders into, through and
out of the successive baths in said tanks, and thence along a drying space,
substantially as described.
8. In automatic electro-plating apparatus the feeding mechanism comprising in
combination a hopper, a rotating drum closing the bottom of said hopper, grooves
in the face of said drum adapted to each receive a single one of the articles to be
fed, a plunger adapted to reciprocate in said grooves and normally retracted by a
spring, a cam adapted to engage said plungers at a fixed point and force them into
said grooves to feed out the articles therein.
9. In automatic electro-plating apparatus the carrier for the articles to be plated,
comprising in combination an endless carrier and means for moving the same, guide
wheels for governing and changing the line of movement of said carrier, holders
attached thereto and adapted to receive and carry the articles to be plated, and
means attached to said carrier for making electrical connection with the circuit
while passing over the plating baths, substantially as described.
10. In automatic electro-plating apparatus the carrier for the articles to be
plated, comprising in combination an endless sprocket belt, sprocket wheels
operated by driven gear for moving said belt, guide wheels for governing and

page_text: changing the line of movement of said belt, and holders secured to said belt for
receiving and conveying the articles, each of said holders being adapted to effect
electrical connection with the circuit while passing over the plating baths,
substantially as described.
11. In automatic electro-plating apparatus the combination of a series of tanks,
an endless carrier arranged to traverse over said tanks, means for moving and
guiding said carrier, holders attached to said carrier and adapted to receive and
hold the articles to be plated and to make connection with the electric circuit while
traversing over the plating tanks, an automatic feeding apparatus comprising a
grooved drum, a hopper, feeding plungers and means for actuating them, a cam for
automatically opening the holders, and means for moving the carrier and feeding
drum at corresponding speed, substantially as described.
12. In electro-plating apparatus, in combination with the plating bath and a
carrier arranged to traverse over the bath and having holders for the articles to
be plated, each of which holders has a projecting contact piece, the negative
contact piece extending above and along the bath in position to be engaged in
moving contact by the contact pieces of the holders while they are passing the
bath, and in electrical connection with the negative side of the circuit, substantially
as described.
13. In electro-plating apparatus a plating tank having a metallic side or sides
electrically connected with the circuit, in combination with the anode and a
conducting support for the anode in contact with the metallic side of the tank,
substantially as described.
Dated this 16th day of July 1894