IMPROVEMENTS IN MEANS OR APPARATUS FOR THE COLLECTION AND DISTRIBUTION OF ELECTRIC CURRENTS
Year: 1881

page_text: LETTERS PATENT to Samuel Alfred Varley, of Hatfield, in the County of
Herts, Electrical Engineer, for an Invention of "IMPROVEMENTS IN MEANS
OR APPARATUS FOR THE COLLECTION AND DISTRIBUTION OF ELECTRIC
CURRENTS."
PROVISIONAL SPECIFICATION left by the said Samuel Alfred Varley at the
Office of the Commissioners of Patents on the 24th December 1881.
SAMUEL ALFRED VARLEY, of Hatfield, in the County of Herts, Electrical
Engineer. "IMPROVEMENTS IN MEANS OR APPARATUS FOR THE COLLECTION AND
DISTRIBUTION OF ELECTRIC CURRENTS."
The contacts which form the poles of the dynamo-electric machines in most
general use are commonly made of metal brushes which rest on opposite sides of
the collector or commutator which is a cylinder built up of segmental conductors
insulated from one another and also from the axle of the machine on which they
are mounted. For efficient working it is desirable that no break should occur in
the electrical continuity between the brushes and the segments. The brushes
therefore require careful adjustment and are so arranged that the segments next in
succession come into electrical contact with the brushes before contact with the
preceding ones is broken. If the brushes get out of adjustment sparking takes
place and the brushes and commutators are in danger of being damaged,
consequently careful supervision is necessary to guard the machines against
injury from this cause. In practice the brushes frequently embrace more than
two of the sections at the same time, these sections being bridged across, and as
there is a difference of electrical potential at the extremities of the bridged sections
a current is always flowing through a portion of the sections locally in succession,
which is so much loss to the efficiency of the machine.
According to my Invention I diminish or obviate these difficulties by causing
the poles to moves in contact with the insulated segments connected to the
armature coils with a rolling friction and I impart to the poles a motion of
rotation equal to or slightly greater or slightly less in circumferential velocity than
the motion of the insulated segments.

page_text: In one form of commutator or collector I employ toothed wheels with insulated
metallic teeth and for simplicity of construction I prefer to make these in the form
of lantern pinions. The number of pins in these lantern pinions corre-pond with
the number of the bobbins or armature sections of the machine and they are
electrically connected to the junctions of the insulated convolutions of the sections.
The number of the lantern pinions which it is convenient to employ depends upon
the number of sections. :
If the machine have, say 32 sections then two lantern pinions would be a
convenient number. These lantern pinions are mounted on the axle of the
machine and the pins of each pinion break joint with the pins of the other pinions.
The junctions of the bobbin sections are connected with the pins of the two lantern
pinions alternately. These pinions work into toothed wheels which I term the
contact wheels mounted in jointed frames capable of adjustment. These said
contact wheels form the collecting contacts and become the poles of the machine.
The pins of the lantern pinions come in contact with the contact wheels in
succession the succeeding pin of (say) lantern pinion No. 2 coming in contact with
the contact wheels before the contact is broken with lantern pinion No. 1. To
make the contact more certain each lantern pinion revolves in gear in two or more
contact wheels placed side by side each one able to move freely with respect to its
neighbours.
Friction or brake springs rest against each of the wheels to keep their teeth in
steady contact with the lantern pins and ensure a certain amount of way or back
lash upon them. There are jointed frames_and_contact_wheels_on_each_side_of_the_
lantern pinions one set forming the positive and the other the negative pole. The
lower ends of the jointed frames are connected by a spring or springs and adjusting
screws mounted on standards press against springs attached to the upper portion of
the frame. These adjusting screws enable the contact wheels to be adjusted and
impart a certain amount of elasticity to them to ensure good contact. The
advantage obtained by arranging the contacts in this way is that they do not get
out of adjustment after they have been once set and therefore constant attention
and skilled supervision are not required. In some cases I find it convenient to
replace the lantern pinions by wheels the periphery of each of which is formed of
insulated segments connected to the junctions of the bobbin or armature sections as
above described in the case of the lantern pinions. Contact wheels mounted on a
jointed frame, which can be adjusted, revolve in contact with these segmental
wheels. On the axle of the machine is mounted a tooth wheel gearing into wheels
arranged on opposite sides of the axle and which communicate motion to the
contact wheels in the jointed frames by means of suitable appliances. I generally
so arrange the parts that the contact wheels and the segmental wheels have a
slightly differential circumferential velocity so as to produce a slight rubbing
action between the two.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by the
said Samuel Alfred Varley in the Great Seal Patent Office on the 24th June
1882.
SAMUEL ALFRED VARLEY late of Hatfield in the County of Herts now of
Islington in the County of Middlesex, Electrical Engineer. "IMPROVEMENTS IN
MEANS OR APPARATUS FOR THE COLLECTION AND DISTRIBUTION OF ELECTRIC
CURRENTS."
The contacts which form the poles of electric generators producing continuous
currents are commonly made of metal brushes which rest on opposite sides of the
collector or commutator which is a cylinder built up of segmental conductors
insulated from one another and also from the axle of the machine on which they
are mounted. For efficient working it is desirable that no break should occur in
the electrical continuity between the brushes and the segments. The brushes
therefore require careful adjustment and are so arranged that the segments next in
succession come into electrical contact with the brushes before contact with the
preceding ones is broken.
If the brushes get out of adjustment sparking takes place and the brushes and
commutators are in danger of being damaged, consequently careful supervision is
necessary to guard the machines against injury from this cause. In practice the
brushes frequently embrace more than two of the sections at the same time, the
intervening sections being bridged across, and as there is a difference of electrical
potential at the extremities of the bridged sections a current is always flowing
through a portion of the sections locally in succession, which is a loss to the
efficiency of the machine.
According to my Invention I diminish or obviate these difficulties by causing
the contact pieces to move in contact with the insulated segments connected to the
armature coils with a rolling friction and I impart to the poles a motion of rotation
equal to or slightly greater or slightly less in circumferential velocity than the
motion of the insulated segments.
In one form of commutator or collector I employ toothed wheels with insulated
metallic teeth and for simplicity of construction I prefer to make these in the form
of lantern pinions.
The number of pins in these lantern pinions corresponds with the number of
the bobbins coils or armature sections of the machine and they are electrically
connected to the junctions of the insulated convolutions of the sections. The
number of the lantern pinions which it is convenient to employ depends upon the
number of sections. If the machine have, say 32 sections then two lantern pinions
would be a convenient number. These lantern pinions are mounted on the axle of
the machine and the pins of each pinion break joint with the pins of the other
pinion.
The junctions of the bobbin sections are connected with the pins of the two
lantern pinions alternately. These pinions work into toothed wheels which I term
the contact wheels mounted in pivotted or jointed frames capable of adjustment.
These said contact wheels form the collecting contacts and become the poles of the
machine.
The pins of the lantern pinions come in contact with the contact wheels in
succession the succeeding pin of (say) lantern pinion No. 2 coming in contact with
the contact wheels before the contact is broken with lantern pinion No. 1. To
make the contact more certain each lantern pinion revolves in gear in two or more
contact wheels placed side by side each one able to move freely with respect to its
neighbours.

page_text: Friction or brake springs rest against each of the wheels to keep their teeth in
steady contact with the lantern pins and to ensure a certain amount of way or
back lash upon them. There are pivotted frames and contact wheels on each side
of the lantern pinions one set forming the positive and the other the negative pole.
The lower ends of the pivotted frames are connected by a spring or springs, and
adjusting screws mounted on standards press against springs attached to the upper
portion of the frame. These adjusting screws enable the contact wheels to be
adjusted and impart a certain amount of elasticity to them to ensure good contact.
The advantage obtained by arranging the contacts in this way is that they do not
get out of adjustment after they have been once set and therefore constant attention
and skilled supervision are not required.
Referring to the accompanying two Sheets of Drawings
Fig. 1 represents a commutator or collector constructed in the form of two
lantern pinions.
Fig. 2 is an end elevation, partly in section, of a commutator or collector together
with contact wheels mounted in pivotted or jointed frames.
Fig. 3 is a back elevation of one of the pivotted frames and its contact wheels.
Fig. 4 is a front elevation of the same.
The two pinions B B, Fig. 1, are mounted on the shaft C, and have each a set
of pins or ', each pin being electrically insulated from all the others and from
the cheeks or flanges and being connected to one of the junctions of the bobbins,
coils, or sections of the armature. The pins of the two pinions break joint, that is
the pins bare set a distance, equal to half their pitch, in advance of or behind the
pins-b DD, Fig. 2, are contact wheels and constitute the poles of the generator.
As shewn in Figs. 3-4 there are two contact wheels at each side of each pinion.
EE, E E are friction or brake springs resting against the contact wheels to keep
their teeth in steady and firm contact with the lantern pins. The contact wheels
revolve on axes carried in frames F and F¹ pivotted at G and G'. The lower ends
of these two frames are connected by the insulated spring J which tends to draw
the contact wheels away from the commutator or collector while their upper ends
carry springs M M which can be set up by the adjusting screws K K to force the
contact wheels against the commutator or collector to ensure good contact.
In some cases I replace the lantern pinions by wheels the periphery of each of
which is formed of insulated segments connected to the junctions of the bobbin or
armature sections as above described in the case of the lantern pinions. Contact
wheels mounted on a pivotted frame, which can be adjusted, revolve in contact
with these segmental wheels. On the axle of the machine is mounted a toothed
wheel gearing into wheels arranged on opposite sides of the axle and which com-
municate motion to the contact wheels in the pivotted frames by means of suitable
appliances. I generally so arrange the parts that the contact wheels and the
segmental wheels have a slightly differential circumferential velocity so as to
produce slight rubbing action between the two.
Fig. 5 is a central section through a commutator or collector formed with
insulated segments.
Fig. 6 is an end elevation shewing such a commutator or collector and also
contact wheels in pivotted or jointed frames according to this part of my Invention.
Fig. 7 is a plan of the same shewing the method of driving the contact wheels,
and
Fig. 8 is a view shewing a back elevation of one set of contact wheels and its
driving mechanism.
B and B (Figs. 5, 6 and 7) are two sets of metal segments fixed round the disc N
of insulating inmaterial attached to the shaft or axis C of the machine or
generator a, b are wires connecting the segments to the junctions of the bobbins,
coils or sections on the armature. D D' are contact wheels running in contact
with the segments of the commutator or collector. Each set of contact wheels D
and D is fixed on a shaft or spindle g. Each of these shafts or spindles carries at
one end a disc or face plate H standing opposite to a crank or crank disc S on

page_text: a shaft Q. This shaft Q is driven by a wheel P from a wheel O on the shaft C,
and communicates its motion to the shaft g through the aforesaid crank and face
plate, the pin of the crank entering a hole or slot in the face plate. This arrange-
ment permits of the contact wheels being adjusted in relation to the collector or
commutator without disturbing the mutual relations of the wheels O and P.
These three wheels have deep shrouds which roll upon each other, and are formed
by preference of leather or vulcanized india rubber.
Each set of contact wheels D and D' is mounted in a frame pivotted at G or G¹.
J is an insulated spring connecting the two frames and tending to move tho
contact wheels away from the commutator or collector, while M M are contact
springs that can be adjusted by the screws KK to force them in the opposite
direction. E E are contact springs bearing on the shafts or spindles G G.
The contact wheels D D' are made either somewhat larger or a little smaller in
diameter than the diameter of the collector wheel B B. The circumferential
velocity of the collector is therefore either somewhat greater or somewhat less than
that of the contact wheels. This ensures a certain amount of rubbing action
which keeps the surfaces clean. The contact wheels I prefer to be cut into teeth
corresponding in number with the segments they come into contact with at each
whole revolution, but they may be plain wheels as represented in Fig. 7. When
I use plain wheels I prefer to make them of a piece of metal tube which I mount
on a disc or ring of vulcanized india rubber and I prefer to coat the surfaces of the
segments of the collector wheels and contact wheels with pure copper or non-
oxydable metal by means of the electrotype process.
Having thus described the nature of the said Invention and the manner in which
it is to be performed I would have it understood that what I consider to be
novel and original and therefore claim as secured to me by the Letters Patent
herein before in part recited is :-
1. The use for receiving the current from or conveying it to the commutator or
collector of an electric generator of a contact piece or conductor constructed and
applied in such a way that it moves in rolling contact with the commutator or
collector but derives its motion otherwise than by the frictional contact of the two
rolling surfaces substantially as described.
2. The use for receiving the current from or conveying it to the commutator or
collector of an electric generator of a contact piece or conductor constructed and
applied in such a way that it moves in rolling contact with the commutator or
collector but derives its motion from a source that drives it with a circumferential
velocity slightly greater or slightly less than that of the commutator or collector
itself substantially as described.
3. The use in combination for the purposes of collection and distribution of
electric currents of a commutator or collector constructed in the form of one or
inore lantern pinions, and contact pieces constructed in the form of toothed wheels
and gearing with the said lantern pinion or pinions substantially as described.
4. The use in combination for the purposes of collection and distribution of
electric currents of a collector having insulated metal segments revolving in contact
with contact wheels, either plain or notched, and, mechanism for driving the said
contact wheels otherwise than by the frictional contact of the two rolling surfaces
substantially as described.
5. In apparatus for the collection and distribution of electric currents wherein
contact wheels roll in contact with a commutator or collector but with a
circumferential velocity slightly greater or less, driving the said contact wheels by
an arrangement of mechanism which permits of their adjustment without
interference with or disturbance of the driving apparatus substantially as
described.
6. The improved apparatus for the collection and distribution of electric currents
constructed arranged and operating substantially as described with reference to
Figs. 2, 3 and 4 of the Drawings.
7. The improved apparatus for the collection and distribution of electric

page_text: currents, constructed arranged and operating substantially as described with
reference to Figs. 6 and 7 of the Drawings.
. In witness whereof I the said Samuel Alfred Varley have hereunto set my
hand and seal, this Twenty fourth day of June in the year of our Lord One
thousand eight hundred and eighty two.
S. ALFRED VARLEY. (L.S.)