IMPROVEMENTS IN ELECTRIC COMMITATORSUTATORS
Year: 1882

page_text: LETTERS PATENT to John Gordon Junior of Dundee in the County of
Forfar North Britain for an Invention of IMPROVEMENTS IN ELECTRIC
COMMITATORS"
PROVISIONAL SPECIFICATION left by the said John Gordon Junior at the
Office of the Commissioners of Patents on the 8th December 1882.
· JOHN GORDON Junior of Dundee in the county of Forfar, North Britain
" IMPROVEMENTS IN ELECTRIC COMMUTATORS
"
The commutators employed in dynamo-electric and such like machines, and in
other cases for altering electrical circuits generally consist of rapidly revolving
cylinders or discs made up of conducting segments insulated from each other and
having stationary rubbers or brushes of conducting material bearing against them.
The friction of the rubbing surfaces is in many cases objectionable as involving
waste of power, and is in all cases a cause of rapid wear and derangement of the
commutator My invention relates to a construction of commutator segments in
such a manner as very greatly to reduce the friction and wear attending their use.
For this purpose I drill along each segment a row or several rows of holes and in
each hole I fix a plug of antifriction material such as that known as metalline.
These plugs presenting themselves on the surface against which the brush or
rubber bears move under it with comparatively little friction and the wear of the
segments as well as of the brushes or rubbers is thus greatly reduced. In cases
where the plugs might be apt to be dislodged by centrifugal force as in a cylindrical
commutator rapidly revolving, I drill the holes slightly taper so as to be somewhat
smaller on the outer side of the segment and thus the plugs inserted in them cannot
be thrown out

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said John Gordon Junior in the Great Seal Patent Office on the
7th June 1883.
JOHN GORDON Junior of Dundee in the county of Forfar, North Britain
"IMPROVEMENTS IN ELECTRIC COMMUTATORS"
The commutators employed in dynamo electric and such like machines, and in
other cases for altering electrical circuits, generally consist of rapidly revolving
cylinders or discs made up of conducting segments insulated from each other and
having stationary rubbers or brushes of conducting material bearing against them.
The friction of the rubbing surfaces is, in many cases, objectionable as involving
waste of power, and is, in all cases, a cause of rapid wear and derangement of the
commutator.
My invention relates to a construction of commutator segments in such a manner
as greatly to reduce the friction and wear attending their use. For this purpose, I
drill along each segment a row or several rows of holes, and in each hole I fix a
plug of antifriction material, such as that known as metalline. These plugs,
presenting themselves on the surface against which the brush or rubber bears,
move under it with comparatively little friction, and the wear "of the segments as
well as of the brushes or rubbers is thus greatly reduced. In cases where the plugs
might be apt to be dislodged by centrifugal force, as in a cylindrical commutator
rapidly revolving, I drill the holes slightly taper, so as to be somewhat smaller on
the outer side of the segment, and thus the plugs inserted in them cannot be
'thrown out.
Fig. 1 of the accompanying drawings is an elevation and fig 2 a section of a
commutator such as is used in the Brush dynamo-electric machines, having its
segments provided with metalline plugs m according to my invention. The holes
for these are a little tapered, as shewn, to prevent the plugs from being ejected by
centrifugal force.
It will be readily understood that commutators of other forms can have their
segments provided with metalline plugs in a similar manner.
Having thus described the nature of my invention and in what manner the same
is to be performed, I claim-
Constructing the commutators of dynamo-electric and such like machines with
plugs of antifriction material secured in holes in their segments and presenting their
ends on the external periphery, substantially as and for the purpose herein set forth.
In Witness whereof, I the said John Gordon, Junior have hereunto set my
hand and seal this fourth day of June in the year of our Lord, one thousand,
eight hundred and eighty-three.
J. J j
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