Improvements in and connected with Electrical Commutators and Collector Rings, and Collectors therefor.
Year: 1895

page_text: Date of Application, 30th Nov., 1895
Complete Specification Left, 15th Jan.. 1896-Accepted, 15th Feb. 1896
PROVISIONAL SPECIFICATION.
Improvements in and connected with Electrical Commutators and
Collector Rings, and Collectors therefor.
I, THOMAS FREDERICK JOHN TRUSS, of 6, Pickering Road, New Brighton,
Cheshire, Electrician, do hereby declare the nature of the said invention to be as
follows:-
This invention relates to those appliances or apparatus by which electrical
currents generated in continuous or alternating current dynamo and similar
electrical generating apparatus are collected therefrom, or by which electrical
currents are conducted to electrically operated apparatus such as electrical motors
and the like, which appliances or apparatus are usually termed commutators or
collector rings.
The present practice is to conduct electrical currents to or from such commutators
or collector rings by means of flat metallic springs or brushes, which bear upon the
periphery thereof, and in use it is found that the face of the commutator and the
extremities of the brushes become quickly worn, owing to the constant friction
between them. The commutator face, inoreover, is usually worn unevenly,
producing crests and hollows which induce sparking to take place between the
commutator and brushes.
In consequence of these defects said brushes and commutator require constant
supervision, and the expense incurred by refacing the commutator and renewing
the brushes is very great.
The present invention has for its object to overcome these defects, and consists,
primarily, of the employment of mercury or liquid as a means of conducting
electrical currents to or from such commutators or collector rings, and, secondly, of
novel forms of commutators or collector rings to be employed therewith.
With the commutator now in common use current is collected from or led to it
by two sets of brushes which bear upon its periphery at points diametrically
opposite to each other, such periphery being built up of segments.
In order to
adapt a commutator to make contact with mercury or liquid contained in cups
disposed beneath such commutator, I divide the commutator into two members,
which two members 1 term the positive and negative members respectively, and
which are mounted on a common axis. Such members are each built up of seg-
ments, each segment of one member being connected by an insulated conductor
with a corresponding but diametrically oppositely disposed segment of the other
member. The segments of one member are connected up with the armature coils
in the usual way.
For collector rings or two-part commutators, as for instance in the Siemens
H armature magneto-generator, each member may consist of a dise of copper, or a
carbon disc laminated between two metallic discs of smaller diameter. In the
latter case discs of lead preferably intervene between the carbon and the other
metallic discs, to prevent fracture of the carbon when clamping them together, and
at the same time insuring good metallic contact. The two members of the
collector rings or commutator are in this instance preferably arranged one on
each side of the armature.
Where three or a similarly small number of segments are required, I provide
each member of a commutator with three copper or carbon discs, but I remove a

page_text: portion, for instance in this case, two-thirds, of such discs and substitute an
insulating material for the portion removed. Each segmented disc is insulated
from the other two discs of the member by laminae of insulating material and from
the spindle or axis by a tube or concentric layer of insulating material. The three
segments of copper or carbon are disposed around the axis so that they form a
continuous copper or carbon periphery. The segments of one member are connected
up with the armature coils in the usual way, by cables which pass through holes in
the intervening discs.
As a means of collecting the current from, or conducting it to collector rings or
commutators such as above described, I employ mercury or a suitable liquid, which
may be contained in cups or troughs disposed underneath each member of the
collector rings or commutator in such a manner that the surface of the mercury or
liquid makes contact with the periphery thereof. Such cups or troughs may
mounted upon a hinged lever, the level of which is adjusted by a set screw; or the
level of mercury or liquid may be maintained by a suitably disposed reservoir.
be
In order to prevent chemical action taking place between the metallic segments
and the mercury, I may platinise the contact surface of such segments, or face
them with carbon or a suitable metal. Where carbon is used for this purpose it
may be secured to the segment by screws, clamps, dovetails, or the like, or be
compressed into the segment, or placed in a cavity therein and run round with
molten lead to secure it.
It will be understood that, where it is desirable, the ordinary metallic spring
brushes may be used with the divided commutator according to this invention,
where the periphery thereof is metallic, as for instance in marine work where the
adjustment of top and bottom brushes during rough weather is inconvenient.
With a divided commutator such brushes may be both disposed on the upper
surface thereof.
By the employment of divided commutators or collector rings and mercurial or
liquid contacts such as above described, the friction and consequent wearing away
of the parts are obviated and sparking is prevented. The machinery therefore
requires less supervision and may consequently be worked more economically.
Dated this 29th day of November 1895.
•
J. A. COUBROUGH,
Registered Patent Agent,
10, St. George's Crescent, Liverpool, Agent for the Applicant.
COME LEIE
Improvements in and connected with Electrical Commutators and
Collector Rings, and Collectors therefor.
I, THOMAS FREDERICK JOHN TRUSS, of 6, Pickering Road, New Brighton,
Cheshire, Electrician, 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 :-
This invention relates to those appliances or apparatus by which electrical
currents generated in continuous or alternating current dynamo and similar
electrical generating apparatus are collected therefrom, or by which electrical
currents are conducted to electrically operated apparatus such as electrical motors
and the like, which appliances or apparatus are usually termed commutators or
collector rings.
The present practice is to conduct electrical currents to or from such commu-
tators or collector rings by means of flat metallic springs or brushes which bear
upon the periphery thereof, and in use it is found that the face of the commutator
and the extremities of the brushes become quickly worn, owing to the constant

page_text: friction between them. The commutator face moreover is usually worn unevenly,
producing crests and hollows which induce sparking to take place between the
commutator and brushes.
In consequence of these defects said brushes and commutator require constant
supervision and the expense incurred by refacing the commutator and renewing the
brushes is very great.
The present invention has for its object to overcome these defects, and consists,
primarily, of the employment of mercury or liquid as a means of conducting
electrical currents to or from such commutators or collector rings, and, secondly
of novel forms of commutators or collector rings to be employed therewith.
With the commutator now in common use current is collected from or led to it
by two sets of brushes which bear upon its periphery at points diametrically
opposite to each other, such periphery being built up of segments. In order to
adapt a commutator to make contact with mercury or liquid contained in cups
disposed beneath such commutator, I divide the commutator into two members,
which two members I term the positive and negative members respectively, and
which are mounted upon a common axis. Such members are each built up of
segments, each segment of one member being connected by an insulated conductor
with a corresponding but diametrically oppositely disposed segment of the other
member. The segments of one member are connected up with the armature coils
in the usual way.
For collector rings or two part commutators as for instance those used in the
Siemens "H" armature magneto-generator, each member may consist of a disc of
copper, or a carbon disc laminated between two metallic discs of smaller diameter.
In the latter case discs of lead preferably intervene between the carbon and the
other metallic discs, to prevent fracture of the carbon when clamping them together
and at the same time insuring good metallic contact. Used as a 2-part commu-
tator, each disc of carbon or copper has inserted in it a zone of insulating material,
the portions of the disc so divided being suitably insulated from the metallic discs
between which they are clamped. The two members of the collector rings or
commutator are in this instance preferably arranged one on each side of the
armature.
Where three or a similarly small number of segments are required, I provide
each member of a commutator with three copper or carbon discs, but I remove a
portion, for instance, two thirds, of such discs, and substitute an insulating material
for the portions removed. Each segmented disc is insulated from the other two
discs of the member by laminae of insulating material and from the spindle or axis
by a tube or concentric layer of insulating material. The three segments of copper
or carbon are disposed around the axis so that they form a continuous copper or
carbon periphery. The segments of one member are connected up with the
armature coils in the usual way by cables which pass through holes in the
intervening discs.
As a means of collecting current from, or conducting it to collector rings or
commutators such as above described I employ mercury or a suitable liquid, which
may be contained in cups or troughs disposed underneath each member of the
collector rings or commutator in such a manner that the surface of the mercury or
liquid makes contact with the periphery thereof. Such cups or troughs may be
mounted upon a hinged lever, the level of which is adjusted by a set screw;
or the level of mercury or liquid may be maintained by a suitably disposed
reservoir.
I will now
proceed to describe the nature of the said invention and in what
manner the same is to be performed, with the aid of the accompanying drawings.
Figure 1 illustrates diagrammatically the principle of my said invention as
applied to a 16-part commutator. It will be seen that the commutator is divided.
into two members A and B, which I term the positive and negative members.
respectively, and which are mounted on a common axis C. Such members are each
built up of segments, numbered 1 to 16. Each segment of the member A is

page_text: connected by an insulated conductor a with a corresponding but diametrically
oppositely disposed segment of the member B. For the sake of clearness only two
pairs of segments are shown thus connected by conductors a in the drawing.
The segments of the member A are connected up with the armature coils of the
electro-generating or electrically operated machine of which the commutator forms
a part, which coils are indicated by the letter D in the figure. Under each
member A. B is disposed a trough containing mercury c and provided with a
conductor d, by which conductor the electric current is conducted to or from the
commutator.
Figures 2 and 3 illustrate in sectional elevation and sectional end view
respectively a 32-part commutator constructed according to this invention, applied
to the armature of a dynamo. It will be seen that the commutator consists of two
members A and B, each comprising 32 segments which are embedded in a core e of
insulating material such as vulcanized-fibre mica, hard wood, or other suitable
material the whole being mounted on the spindle f of the armature, which is
designated E. A collar g serves to bind the feet of the segments and to strengthen
the commutator. It will be seen that the commutator is insulated from the
spindle and may be mounted thereon in a similar manner to the ordinary
commutator. The segments 1 to 32 are preferably of copper and are cach
provided at their outer ends with a facing or contact piece of carbon h which is
dovetailed into the segment and secured by molten lead. Each segment has
formed upon it a lug i to which is attached the armature coils, and a lug k to
which is attached an insulated conductor a leading to a corresponding lug upon the
diametrically oppositely disposed segment of the other member of the commutator.
The collectors consist of troughs 6 mounted upon an arm I pivotted at m and
provided with an adjusting screw n loosely mounted in the socket n', and wheel n².
The surface of the mercury c is adjusted to the periphery of the members A. B by
means of the screw n which raises or lowers the arm 1. A cable d, suitably
attached to the arm conducts current to or from the commutator. The pivot m
and screw device n are insulated from the bedplate p by insulating material pl.
Figures 4, 5, 6 and 7 illustrate a modified form of commutator according to this
invention, Fig. 4 being a front view thereof, and Figs. 5 to 7 views of the
commutator segment discs. The modification consists in arranging the segments
of the commutator in laminae, and is particularly adaptable where segments
composed wholly of carbon are used. In the example shewn each member A. B
consists of 3 segments, numbered 1 to 3. The segments consist of carbon
forming of a circle, the remaining consisting of insulating material such as
vulcanized-fibre, slate, porcelain, or other suitable material. Each segment is
separated from its fellows by discs of insulating material, and from the armature
spindle f by a sleeves of the same material. Between the segment dises and the
insulating dises I prefer to insert discs t of lead, to prevent fracture of the carbon
when the members A. Bare tightened up by the nuts it, and to these leaden discs
the inter-segmental conductors a and armature coils D are electrically connected.
Each segment of the positive member A is electrically connected with a
diametrically oppositely disposed segment of the negative member B, as in the
diagrammatic Fig. 1., by insulated conductors which, as do also the armature
coils D, pass through holes in the intervening discs. In Figs. 5, 6 and 7 the
shaded segments represent the segments of the positive member A, whilst the
blackened segments represent the position of the corresponding segments of
the negative member B. The mercurial collector troughs may be arranged as
described with reference to Figs. 2 and 3.
Figure 8 represents the application of collector rings and mercurial collectors
according to this invention to alternate current generating machines, a simple
Siemens "H" armature being shewn. The collector rings consist of two complete
discs of carbon F, suitably mounted upon and insulated from the spindle f of the
armature E. Leaden discs t are inserted between the carbon disc F and the
metallic clamping discs t¹ to prevent fracture of the carbon when the discs are

page_text: tightened up by the bolts t. The armature coils D are electrically connected with
the discs as shewn. The mercurial collector troughs may be arranged as
described with reference to Figs. 2 and 3.
The collector discs F shewn in Figure 8 may be transformed into a 2-part
commutator by inserting a zone of insulating material in each disc and suitably
insulating the portions of the disc so divided from the metallic discs between which
they are clamped.
Figure 9 represents a modified form of collector trough b, in which the contact
level of the mercury c is adjusted by a piston working in a reservoir of
mercury 2. The weight of the piston 6 tends to force the mercury up towards the
periphery of the commutator (A-B) and the weight is adjusted by a wheel-nut 63
working on the piston spindle 64, the nut abutting against the cover of the
trough. The advantage of this form of trough and reservoir is that by lifting the
piston by means of the handle the mercury rises in the reservoir and recedes
from the periphery of the commutator, thus instantly breaking the main circuit.
A plug or cock w is provided, by which the mercury may be drained from the
trough.
It will be understood that although I have, in the above description relating to
the figures of the drawings described the contact surfaces of commutator segments
and collector rings as being of carbon, such segments or rings may be wholly
metallic, and in order to prevent chemical action taking place between their surface
and the mercury I may platinise the contact surface thereof. Where carbon is
used as a contact surface it may be secured to the segment or ring by screws,
clamps, dovetails, or the like, or be compressed into the segment or ring, or placed
in a cavity therein and run round with molten lead to secure it.
Although divided commutators and mercurial collectors according to this inven-
tion have, in the drawings hereto annexed, only been illustrated as applied to
electro-generating machines, they are equally applicable to many forms of
electrically operated machines.
It will also be understood that, where it is desirable, the ordinary metallic
spring brushes may be used with the divided commutator according to this invention,
where the periphery thereof is metallic, as for instance in marine work where the
adjustment of top and bottom brushes during rough weather is inconvenient. With
a divided commutator such brushes may be both disposed on the upper surface
thereof.
In place of mercury being used in the collector-troughs above described, I may
employ sulphate of copper. Acidulated water may be used with platinized or
carbon contacts or segments, in troughs of glass or porcelain containing a conductor;
or metallic troughs with platinized interiors may be used. With such liquids as
collectors I provide the segment faces with knife-edge or diamond shaped projections,
adapted to cut through the liquid without elevating it. The periphery of the
commutator between such projections may be coated with a greasy surface or
formed with rebates in order to prevent the liquid from spreading over such surface
and thus short-circuiting the segments.
By the employment of divided commutators or collector-rings and mercurial or
liquid collectors such as above described, the friction and consequent wearing away
of the parts, above referred to, are obviated, and sparking is prevented. The
machinery therefore requires less supervision and may consequently be worked more
economically than heretofore.
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed, I declare that what I
claim is
--
1. The employment of mercury (or liquid such as above described) as a means of
collecting electrical current from or conducting it to commutators or collector rings
of electro-generating or electrically-operated machinery, substantially in the manner
herein set forth.

page_text: 2. Commutators of electro-generating or electrically-operated machinery, com-
prising two members arranged to receive or transmit positive and negative currents
respectively, each member being built up of segments or insulated pieces and each
segment of one member being electrically connected with a diametrically oppositely
disposed segment of the other member of the commutator, arranged, constructed
and operating substantially in the manner herein set forth.
3. The combination with collector rings of alternate current electro-generating
machinery or with commutators of electro-generating or electrically operated
machinery, comprising two members arranged to receive or transmit positive and
negative currents respectively, constructed and operating substantially as herein
set forth, of collectors consisting of troughs containing mercury, or liquid such as
herein described, the surface of which makes contact with the peripheries of said
rings or members of said commutators, arranged and operating substantially as herein
set forth.
4. Providing the contact faces of commutator segments and collector rings with
which are employed mercurial collectors in the manner hereinabove described, with
carbon or platinised surfaces for the purpose herein described.
5. The particular arrangement and construction of commutator and collectors
hereinabove described with reference to Figures 2 and 3 of the drawings hereto
annexed.
6. The particular arrangement and construction of commutator hereinabove
described with reference to Figures 4 to 7 of the drawings hereto annexed.
7. The particular arrangement and construction of collector rings and collectors
hereinabove described with reference to Figure 8 of the drawings hereto annexed.
8. The particular arrangement and construction of collector trough and mercury
reservoir hereinabove described with reference to Figure 9 of the drawings hereto
annexed.
Dh 19th L
T1006
J. A. COUBROUGH,
Registered Patent Agent,
10 St. George's Crescent, Liverpool, Agent for the Applicant.