Improvements in Tools or Appliances for Use in the Trueing-up, Scouring, or like Treatments of Dynamo Electric Machine Cylinders and the like.
Year: 1894

page_text: Date of Application, 13th Nov., 1834
Complete Specification Left, 11th Sept., 1895-Accepted, 26th Oct., 1895
PROVISIONAL SPECIFICATION.
Improvements in Tools or Appliances for Use in the Trueing-up,
Scouring, or like Treatments of Dynamo Electric Machine
Cylinders and the like.
We WALTER POYNTER ADAMS of Mansion House Buildings, in the City of
London, Electrical Engineer, and ROOKES EVELYN BELL CROMPTON, of Mansion
House Buildings aforesaid, Electrical Engineer, do hereby declare the nature of
this invention to be as follows:-
Our invention consists in improvements in a tool or appliance preferably
portable for trueing up, scouring, polishing or cleaning the commutators or
collecting cylinders of dynamo electric machines, motors or the like. Up to the
present such cleaning and polishing as is necessary to be carried out by the
attendant in charge has been by means of emery or other scouring cloth of
varying degrees of fineness either held in the hand or applied by a pad having a
soft surface or applied to a block of wood hollowed out to fit truly to the surface
of the commutator. This last method of applying the scouring cloth is preferable
to others as it has a tendency to maintain a true cylindrical surface on the
commutator whereas if the scouring cloth is applied by hand or by a soft pad there
is a tendency to wear away the depressions as well as the prominences and so
aggravate the "untruth" of the cylindrical surface.
The chief difficulties in applying the hollowed out wood block is that as the
commutator wears away and is cousequently reduced in diameter the wooden block
no longer fits it and a fresh one must be provided.
To obviate this difficulty we employ a flexible strip of metal or other suitable
material of the correct thickness and stiffness to accommodate itself generally to
the cylindrical form of the commutator but not to adapt itself to the smaller
depressions. We generally mount this strip in a forked arm and attach it thereto
by hinged arms or other appliances in such a manner that the mere action of
pushing or pulling the strip up against the cylindrical surface of the commutator
causes the strip to adapt itself to the cylindrical surface sufficiently for our purpose
but other methods of applying the strip will readily suggest themselves.
In this
The scouring cloth or other flexible polishing material that we use can be readily
held in the required position by a suitable clip or clips but in some cases
may bo
simply held in position by hand. In some cases where very great exactness is
required we attach to the surface of the strip, blocks of the pitch or pitch like
substance that is usually employed by lens or spectacle polishers. By polishing
pitch we mean any pitchy substance which has the true liquid but extremely
viscous nature of pitch-which qualities peculiarly fit it for this purpose.
case the strip may be somewhat stiffer and less yielding than that required for
carrying a scouring cloth. The pitch may be applied in an even layer to the
working surface of the strip and the pitch itself may be divided or sawn across
at short intervals. The strip thus covered with pitch can then be applied to the
revolving surface of the commutator and it will adapt itself to the cylindrical
surface with great exactness, the polishing or scouring material can then be applied
to and will embed itself in the surface of the pitch.
Dated the 0th day of November 180.1
WM. BROOKES & SON,
55 & 56 Chancery Lane, London, Agents for the Applicants.

page_text: COMPLETE SPECIFICATION.
Improvements in Tools or Appliances for Use in the Trueing-up,
Scouring, or like Treatments of Dynamo Electric Machine
Cylinders and the like.
We WALTER POYNTER ADAMS of Mansion House Buildings, in the City of
London, Electrical Engineer, and ROOKES EVELYN BELL CROMPTON of Mansion
House Buildings aforesaid, Electrical 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:—
Our invention consists in improvements in a portable tool or appliance for
trueing up, scouring, polishing or cleaning cylindrical surfaces more especially the
commutators or collecting cylinders of dynamo electrical machines or motors
Up to the present such cleaning and polishing of commutators as is necessary to
be carried out by the attendant in charge has been by means of emery or other
scouring cloth of varying degrees of fineness either held in the hand or applied by
a pad baving a soft surface or applied to a block of wood hollowed out to fit truly
to the surface of the commutator. This last method of applying the scouring cloth
is preferable to others as it has a tendency to maintain a true cylindrical surface on
the commutator whereas if the scouring cloth is applied by hand or by a soft pad
there is a tendency to wear away the depressions as well as the prominences and so
aggravate the "untruth" of the cylindrical surface.
The chief difficulties in applying the hollowed out wood block is that as the
commutator wears away and is consequently reduced in diameter the wooden block
no longer fits it and a fresh one must be provided. To obviate this difficulty we
employ a flexible strip of metal or other suitable material of the correct thickness
and stiffness to accommodate itself generally to the cylindrical form of the commu-
tator but not to adapt itself to the smaller depressions.
We generally mount this strip in a forked arm and attach it thereto by hinged
arms or other appliances in such a manner that the mere action of pushing or
pulling the strip up against the cylindrical surface of the commutator causes the
strip to adapt itself to the cylindrical surface sufficiently for our purpose but other
methods of applying the strip will readily suggest themselves.
The scouring cloth or other flexible polishing material that we use can be readily
held in the required position by a suitable clip or clips but in some cases it may be
simply held in position by hand.
In some cases where very great exactness is required we attach to the surface of
the strip, blocks of the pitch that is usually employed by lens or spectacle polishers.
By polishing pitch we mean any pitchy substance which has the true liquid but
extremely viscous nature of pitch, which qualities peculiarly fit it for this purpose.
In this case the strip may be somewhat stiffer and less yielding than that required
for carrying a scouring cloth.
The pitch may be applied in an even layer to the working surface of the strip
and the pitch itself may be divided or sawn across at short intervals. The strip
thus covered with pitch can then be applied to the revolving surface of the
commutator and it will adapt itself to the cylindrical surface with great exactness,
the polishing or scouring material can then be applied to and will einbed itself in
the surface of the pitch.
When it is desired to true up or polish the commutators and motors when the
motor is caused to revolve driven by current passing through its own commutator
we use a polisher of our construction in which the flexible strip is made of non-
conducting material and the forks are made of such distance apart as to make the
curved portion of strip embrace as large an are of the commutator as possible
without running the risk of disturbing the brushes.

page_text: In another method we polish the commutator of a running motor by substituting
for its ordinary brushes small ones of less than the usual width and apply a polisher
which embraces the ordinary length of arc with flexible strip of non-conducting
material to that portion of the commutator on which the brushes do not rest, and
in another method we cause the motor to revolve by putting two narrow brushes
to press up against the end of the commutator and thus leave the cylindrical
portion of the commutator entirely free for polishing purposes.
DESCRIPTION OF THE DRAWINGS.
The accompanying drawing shews the side view of a polisher intended for
A is a flexible
trueing up the commutators of dynamo machines or of motors.
strip of any suitable material which is varied in width to suit the particular
The fork E
commutator it is intended to polish. E and F are supporting arms.
in this case being solid with the handle and the other fork F being hinged at the
point C, and capable of adjustment by the arm and screw D. This enables the strip
to adapt itself within limits to commutators varying in diameter. The polishing
surface, which may be of any convenient form of emery cloth or similar material,
is supported by the flexible strip A as shown in the drawing, and is held in position
at B by a clip one end, the other end being left free. In most cases it is not
necessary to secure the second end of the polishing cloth, but in such cases where
it is necessary a second clip can be added but instead of being as B a spring clip, it
may be a removable one.
In cases where it is necessary to use pitch blocks instead of the polishing cloth
they are attached to the concave surface of the strip A.
Having now particularly described and ascertained the nature of our said inven-
tion and in what manner the same is to be performed, we declare that what we
claim is :-
1. In machinery for trueing up or polishing cylindrical surfaces the use of a
flexible strip in combination with one or more hinged arms attached to a back
substantially as described.
2. For polishing cylindrical surfaces (where considerable accuracy is required)
the employment of pitch segments to support the flexible rubbing surface
substantially as described.
3. For scouring the commutators of electrical machinery substantially as
described.
4. In cleaning the commutators of motors, making such arrangements of brush
gear and commutator as to enable the polisher to be applied effectively when the
current is passing through the armature.
5. In cleaning the commutators of motors revolved by their own current the use
of the special devices therein described to enable a polisher to be applied effectively
when the current is passing through the armature.
Dated the 10th der of Santember 1895
WM. BROOKES & SON,
55 & 56 Chancery Lane, London, Agents for the Applicants.