Improvements in Brushes for Dynamos.
Year: 1892

page_text: Date of Application. 16th Aug., 1892-Accepted, 24th Sept., 1892
COMPLETE SPECIFICATION.
Improvements in Brushes for Dynamos.
A communication by HOWARD HENRY CHERRY, SEWARD DEVUR YOUNGLOVE,
LOUIS HOUSE, and WILLIAM CHANDLER RAYMOND, all of Syracuse,
County of Onondaga, State of New York, United States of America.
I, 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 those devices denominated dynamo or commutator
brushes, designed as a medium for the transmission of electricity from the com-
mutator of a dynamo to wires for distributing same, arranged as usual.
The object of the invention is to provide a dynamo brush so constructed as to
ensure its thorough ventilation, requisite elasticity yet needful rigidity, durable
and effective, economical of manufacture,. forming in fact a perfect brush that will
not spark, gum or burn, nor cut the commutator; important requisites.
Referring to the accompanying drawings
Higure is a top plan of the brush:
:-
Figure 4, a transverse section enlarged, taken at x x, Figure 1;
Figure 5 a detail, greatly enlarged, illustrating wire fabric utilised in construc-
tion.
Like letters and figures indicate corresponding parts throughout the views of the
drawing.
In this drawing-
1 denotes the brush: A, the laminar core thereof, comprising folds or layers a,
formed of strip or strips of wire fabric (or finely perforated metallic plates)
terminating edge-wise lineal, as at b, said layers preferably created by reverse
folding of a wire fabric, see c; although, evidently, individual pieces laid one upon
another are employable.
B indicates a wrapper, of wire fabric (or perforated metal), tightly enclosing
from end to end the core A, a lap-joint d firmly uniting the meeting edges of
wrapper.
The rough edges e of the core fabric intermeshing the spaces in the wrapper-
fabric, longitudinal displacement one from the other is impossible.
C is a longitudinally adjustable shield, of sheet metal or other electric-con-
ducting material, partially enclosing wrapper B of the core, which shield comprises
a flat portion, having laterally guide ways g for the loose reception of the con-
tiguous portions of the wrapper of the core.
are ventilating holes in the shield, acting as ventilators.
In practice, the ventilating spaces i, created in the wire fabric of the core and
wrapper incident to, the weaving of the wire cloth, prove sufficient for all needful
ventilation of the brush, ensuring a uniformly cool brush, and which, from its
peculiar construction, operates sparkless, is non-burning, cannot gum, nor cut the
commutator, is sufficiently ductile and pliable with all requisite stiffness, of highest
efficiency created by the novel arrangement of the woven wires creating the fabric
body and producing, in its entirety, a practically perfect brush.
No oil or other lubricant is essential to this brush, it being impossible for it to

page_text: become gummed or clogged, the ventilating spaces i in its body for circulation of
air preventing lodgment of dust, etcetera, thus obviating gumming or stickiness of
the brush or commutator.
K is the commutator-contact end of brush, bevelled or concaved to conform to
the periphery of the commutator of a dynamo.
The shield C is longitudinally movable on the wrapper B to permit of requisite
projection of the brush body at its contact extremity.
Said shield acts as a stiffener, while coincidently allowing sufficient pliability of
the contact extremity of the brush body.
The flat part of the shield receives impingement of the binding screw usual
to a brush holder, thereby shielding the ductile core and wrapper from wear or
puncture by the screw.
By a lap joint connection of the overlapping edges of the wrapper, secure
attachment is afforded, far superior to soldering or stitching thereof.
Preferably, copper or brass fabric is employed.
Obviously, modifications of this construction are possible, involving no departure
from the real scope of this invention.
The value, utility and advantages, and inexpensiveness of this brush are readily
apparent, obviating, as it does, the defects and drawbacks incidental to the ordinarily
employed forms.
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 correspondents, I declare that what I claim is :-
1. A ventilated brush for dynamos, consisting of a perforated core, a perforated
wrapper enclosing it, and a shield movably attached to said wrapper, substantially
as described.
2. A brush for dynamos, comprising a perforated core formed of folds or layers
of wire fabric, a perforated wrapper of wire fabric surrounding same, and a
shield or clasp secured longitudinally movable on said wrapper, substantially as
described.
3. A ventilated dynamo brush, comprising a laminar perforated body and a
longitudinally adjustable shield or clasp attached thereto, substantially as
described.
4. In a ventilated brush for dynamos, a perforated laminar core of electric con-
ducting material, a perforated electric-conducting wrapper or binder enclosing same
immovably, the meeting edges of the wrapper interlocked by a lapped joint, and a
shield or guard of electric-conducting-material movably secured to the wrapper,
substantially as described.
5. In a dynamo brush, a perforated laminar core, a wrapper thereto, said core
and wrapper be coincidently bevelled or concaved at an end, and a shield plate
attached movably to the wrapper portion, substantially as described.
6. A ventilated dynamo brush made of perforated metallic layers retained
together by a perforated metallic wrapper extending the length of the layers,
substantially as described.
7. A ventilated brush for dynamos, formed of layers of wire fabric wherein the
individual wires in one direction are parallel to the axis of a commutator, and the
other individual wires transversely to said axis, substantially as described.
8. A ventilated dynamo brush, comprising a sheet or sheets of wire fabric
disposed in folds held contiguous to each other, substantially as described.
Dated this 15th day of August 1892.
WM. P. THOMPSON & Co.,
Agents for the Applicant.