Improvements in and connected with Dynamo Electric Machinery.
Year: 1898

page_text: Date of Application, 7th Mar., 1898-Accepted, 30th July, 1898
COMPLETE SPECIFICATION.
Improvements in and connected with Dynamo Electric Machinery.
We, MONTAGUE TABOR PICKSTONE, ROLAND SYDNEY PORTHEIM, and ARTHUR
CHARLESWORTH PEEBLES, all Electrical Engineers, of the Firm of David Bruce
Peebles & Co., Engineers, Tay Works, Edinburgh, in the County of Midlothian,
Scotland, 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:-
The invention relates to the mechanical details of the following essential parts:--
(1) A new and improved form of self oiling bearing.
(2) A new and improved form of commutator.
(3) A new and improved form of brush holder.
(4) A new and improved form of coil former insulation.
The first part of our invention, relating to a new and improved form of self
oiling bearing, consists in taking a metal cover, preferably of annular section, and
attaching thereto two metal bosses, truly bored and turned, and attached by means
of set screws or in any other suitable manner to before mentioned metal cover,
which latter is provided with a truly bored and recessed hole, forming in conjunc-
tion with the two circular bosses, a complete bearing, the circular recess in central
cover acting as an oil well. In conjunction with the above mentioned bearing, a
suitable sleeve or sleeve of anti-friction metal may be used, the lubrication being
effected by means of a loose ring running on the shaft, or a fixed ring of suitable
shape.
As an alternative to the above, one of the circular bosses may be cast in one
with the central portion, leaving one only removeable.
The second part of our invention, relating to a new and improved form of com-
mutator, where it is essential to cross connect any combination of commutator
bars, consists in attaching copper connecting pieces to the inside of the commu-
tator sections, and after suitably insulating same, clamping the whole together
by means of circular metal bush rings.
Thus we are enabled to house all the cross connecting strips within the commu-
tator itself, thereby economising space and ensuring mechanical rigidity.
The third part of our invention, relating to a new and improved type of brush
holder, consists of a metal casting, the upper portion of which is machined out to
form a suitable slide, and to the bottom portion of which is fixed a circular disc, which
in its turn is rigidly attached to rocker spindle or other form of suitable bracket.
A circular metal sleeve, provided with two projections, revolves on the before
mentioned disc, and one of these projections presses against a similar projection
fixed on to the brush carrier casting, thereby imparting a directly forward motion
to the brush carrier. The other projection on the circular sleeve contains a com-
pression screw which presses against a suitable spring which is in abutment with
the fixed circular disc. This spring, being always in compression, transmits a
very positive though flexible controlling force to the brush carrier thereby reduc-
ing vibration to a minimum without resorting to excessive brush pressure.

page_text: A metal guide bar, for feeding up brushes as they wear, with suitable spring
for preventing the backing out of same is provided. Suitable holding off gear
is also supplied.
The fourth part of our invention, relating to a new and improved form of
insulated coil former, consists of a metal coil former or spool-adapted for field
magnet winding, and covered on the surface with one or more coatings or layers
of. porcelain, glass, or other suitable insulating enamel of like nature.
"
In the annexed drawings, referring to (1) A new and improved form of
bearing" (Sheet 1. Figs. 1, 2,)-C, represents the above mentioned annular
cover, G, G, the circular end bosses, S, the shaft, L, L, the anti-friction liner, R,
the loose oil ring, which may be replaced by a fixed oil thrower, as mentioned
above, B, the annular recess in main casting, forming the oil bath, N, N, notches
cut in anti-friction or other sleeve to allow clearance for oil ring. It should be
noted that where a fixed oil thrower is used, the bush L, L, is divided into two
halves, this alternative arrangement is not shewn in drawing.
In the annexed drawings, referring to (2) "A new and improved form of commu-
tator" (Sheet 2 Figs. 1, 2) C, C, represent the copper connecting strips attached
to the inside of the commutator sections as shewn at S, S. I, I indicate micauite
or other suitable insulation. B, B, represent metal bushes and rings clamping
the whole firmly together.
is
a
or
a
In the annexed drawings referring to (3) "A new and improved form of brush
holder" (Sheet 3, Figs. 1, 2, 3) A, represents a circular bush mounted on a
spindle, A 1, screwed into the brush holder piece, A 2, and held from turning on
the spindle by a locking pin, A 3, formed on a washer, A 4. B, is the brush holder
which works in a slide, S, and is suitably formed to receive a brush, E1. C,
which
circular metal sleeve
is free to rotate on the circular
brush disk, A, and is formed with
projection or tooth, P1,
working in a rack, T, formed on the brush holder, B. A metal guide feed bar, E,
for feeding up the brush, E1, to take up wear, is fixed on the inner end of the
feeding screw, Z 1, by a pin, Z2. A spring piece, Z3, fixed on the brush holder, B,
is provided with a locking pin, Z4, which bears up against the feeding screw, Z1,
preventing it from returning, thereby also preventing the movement of the feed
bar, E, and the brush, E1, when their position has been fixed in the brush
holder, B. S1, is a spring which rests in a recessed part, S2, of the fixed circular
bush, A, and a screw, G, working in a projecting part, P, of the sleeve, C, is
employed to compress it to any suitable extent. The compression of the spring, S 1,
gives a rotary motion to the sleeve, G, which by means of the tooth, P1, acting
on the rack, T, imparts a directly forward motion to the brush holder or carrier, B.
The holding off gear for the brushes consists of spring piece, Z5, fixed on the
sleeve, C, and provided with a locking pin, Z6, so that when the sleeve is turned
sufficiently to draw back the brush carrier, B, and with it the brush, E1, the pin
drops into a recess, Z7, in the fixed disk, A, and thereby locks or retains the
brush in the desired position.
C
In the annexed drawings referring to (4) A new and improved form of coil
former insulation" (Sheet 4, Figs. 1, 2,) S, S, represents the metallic coil former
or spool, which may be of any other form adapted for coil winding for electrical
purposes, E, E, represents a stratum of glass, porcelain or other similar insulating
enamel. The thickness of this stratum of enamel depends on the electrical pres-
sure or voltage to which the coil will be subjected.
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) A new and improved form of bearing, involving the combination of two or
more separate parts, and arranged in such a way that the central portion forms
the oil bath. The two circular bosses form the bearing, or one only may be used,

page_text: being cast in one with the central portion. All as designed and illustrated with
reference to the above descriptions and accompanying drawings. (see Sheet 1,
Figs. 1, 2).
(2) An improved cross connected commutator, having the cross connectors
inclosed within, and forming part of the commutator itself, in accordance substan-
tially with Sheet 2, Figs. 1, 2, and accompanying description.
(3) An improved form of brush holder, involving the conversion of a rotary
movement into a rectilinear movement, through the agency of a spring in com-
pression and a rack and pinion motion, and acting on a slide carrier, in accordance
substantially with Sheet 3, Figs. 1, 2, 3, and accompanying description.
(4) An improved form of insulated coil former involving the combination of a
metallic former or spool and a covering of glass, porcelain, or other similar insulat-
ing enamel of like nature. This enamel electrically insulating the wire or strip
from the metallic spool on which it is wound, as explained in above description,
with reference to accompanying drawings:-(Sheet 4, Figs. 1, 2,).
MONTAGUE TABOR PICKSTONE.
ROLAND S. PORTHEIM.
ARTHUR C. PEEBLES.
Applicants.
MONTAGUE TABOR PICKSTONE.
ROLAND S. PORTHEIM.
ARTHUR C. PEEBLES.
Applicants.