Improvements in the Construction of Dynamo-electric Machines and Electro-motors.
Year: 1894

page_text: Date of Application, 28th July, 1894
Complete Specification Left, 8th Dec., 1894-Accepted, 12th Jan., 1895
PROVISIONAL SPECIFICATION.
Improvements in the Construction of Dynamo-electric Machines and
Electro-motors.
We, THOMAS PARKER LIMITED, of Albany Chambers, Lichfield_Street,
Wolverhampton in the County of Stafford, Electrical Engineers, and THOMAS
PARKER, Managing Director of the said Company, do hereby declare the nature
of this invention to be as follows:-
--
This invention has for its object, firstly, to facilitate the cleaning and the removal
and replacement of the armature of a two-pole single-limb dynamo-electric machine
or electro-motor in which the armature and pole-pieces stand above or outwards
from the magnet coils, and also the removal and replacement of the ferrules which
carry the coils which surround the magnets; secondly to alter, with a view to
facilitating their preparation, the form of certain parts of the pole-pieces which have
been previously devised to enable the object above stated to be effected; and thirdly
to improve the bearings of dynamo-electric machines and electro-motors which are
lubricated by means of lubricating rings.
According to the first part of this invention, the upper or outer portions of the
pole-pieces of a two-pole single-limb dynamo-electric machine or electro-motor are
hinged to the lower or inner portions thereof, respectively, so that they may be
turned back on their hinges to expose half of the cylindrical surface of the
armature at a time, and thus allow the armature to be readily cleaned and, if desired,
lifted out of its bearings and removed from the machine; and the hinged portions
of the pole-pieces may be turned up into such position as not to overhang or project
beyond the plane of either the inner or outer face of the portion of the corre-
sponding magnet around which the coils pass, and thus the ferrules carrying the
magnet coils may be readily drawnfrom off the magnets and over the pole-pieces, and
be replaced as desired. The joint or division line at the inner face of each pole-
piece between the hinged portion thereof and the fixed portion, may be as far
upwards or outwards from the transverse axis of the armature as will allow of the
armature being readily drawn up from between the fixed portions of the pole-pieces
when the hinged portions are turned back, and thus considerably more than half
the total lines of force passing from a pole-piece to the armature will pass
exclusively through the fixed portion of the pole-piece. In order to leave as much
metal as possible in the part of each fixed portion of a pole-piece which is above
the transverse axis of the armature, and to increase the area of the joint so as to
reduce to a minimum the magnetic resistance of the joint, and to lighten the hinged
portion of each pole-piece, the joint or division line aforesaid is formed to slant
upwards from the inner face of the pole-piece. It is preferred to construct the
hinged joints with projections from the hinged portions of the pole-pieces, which fit
within recesses formed in the fixed portions, so as to leave no projections from the
fixed portions, whereby the machining of the fixed portions is facilitated. Any
convenient form of hinge may, however, be adopted. The outer angle or shoulder
of each hinged portion of a pole-piece is formed to slant off from the hinged joint
to the top when in its normal position, so that when such portion is turned back
sufficiently for the ferrule to clear the inner side thereof, the outer corner will not
overhang or project from the plane of the outer side of the magnet. Each hinged
portion of a pole-piece is firmly held down, when closed down on to the fixed portion

page_text: thereof, by means of a bolt (or bolts) which passes through a hole formed therefor
in the hinged portion and is screwed into the fixed portion; and the heads of these
bolts may be formed with loops or eyes for use in lifting the machine.
Prior to the present invention, portions of the pole-picces of two-pole single-limb
dynamo-electric machines and electro-motors have been made removable for the
purpose of facilitating the cleaning and removal of the armature, and the removal of
the ferrules from the magnets. These removable pieces have been formed with slanted
outer sides to fit between correspondingly-shaped inner sides of the upper portions
of the fixed parts of the pole-pièces. The fitting truly together of inclined surfaces
is, however, a very expensive and difficult operation. Now, according to the secont
part of this invention, such removable pieces are formed with their outer sides struck
from a common centre, so that they may be turned true in a lathe, and faces against
which they bear are correspondingly shaped so that they may be readily formed
true by boring.
•
This method of fitting the parts together is much cheaper and simpler than that
previously adopted. The removable pieces are fixed to the grid as heretofore, and
may thus be conveniently centred for turning.
Bearings lubricated by lubricating rings which dip into oil reservoirs have here-
tofore had both the top and bottom steps or brasses divided transversely, so as to
leave a gap or passage for the ring.
Now, according to the third part of this invention, the bottom step or brass is
formed continuous throughout its entire length, and the ring is formed in two parts
which are hinged together and with a spring catch or any suitable form of fastening
by which it may be held closed up; and the ring is put in place by first opening. it
out and passing it around both the shaft and the bottom step or brass, and then
clusing it up and fastening the closed parts together. A convenient method of
forming the ring is to make it similar to a bracelet which is formed to close up
around the arm but to leave no projections. A modification of this part of the
invention consists in supporting the bottom step or brass in a manner which leaves
it clear underneath for some distance from one end, such as by forming its inner end
as a bracket by means of which it is fixed to the framing, or by supporting it on a
plate which leaves it clear at the outer end and along the sides towards such end,
so that a solid or ordinary ring may be pushed over the shaft and under the step or
brass before the top step or brass is put in position.
Dated this 27th day of July 1894.
STEPHEN WATKINS,
Wolverhampton, Agent for the Applicants.
Imp.ovements in the Construction of Dynamo-electric Machines and
Electro-motors.
We, THOMAS PARKER, LIMITED, of Albany Chambers, Lichfield Street,
Wolverhampton in the County of Stafford, Electrical Engineers, and THOMAS
PARKER, Managing Director of the said Company, 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 has for its object, firstly, to facilitate the cleaning and the removal
and replacement of the armature of a two-pole single-limb dynamo-electric machine
or electro-motor in which the armature and pole-pieces stand above or outwards
from the magnet coils, and also the removal and replacement of the ferrules which
carry the magnet coils; and, secondly, to alter, with a view to facilitating their
preparation, the forms of certain parts of the pole-pieces which have been previously
devised to enable the object above stated to be effected.

page_text: According to the first portion of this invention, the upper or outer portions of
the pole-pieces of a two-pole single-limb dynamo-electric machine or electro-motor
are carried by the lower or inner portions thereof, respectively, in such manner that
they may be turned back to expose half (or approximately half) of the cylindrical
surface of the armature at a time, and thus allow the armature to be readily
cleaned and, if desired, lifted out of its bearings and removed from the machine;
and such upper or outer portions of the pole-pieces may be turned back into such
position as not to overhang or project beyond the plane of either the inner or
outer face of the portion of the corresponding magnet limb around which the coils
pass, and thus the ferrules carrying the magnet coils may be readily drawn from
off the magnet limbs and over the pole-pieces, and be replaced as desired.
For the purpose of enabling the upper or outer portions of the pole-pieces to be
turned back as described, it is preferred to hinge them to the lower or inner
portions; and a convenient means of carrying out this part of the invention is
illustrated by Figures 1, 2 and 3 of the drawings herewith, of which
Figure 1 is an elevation, partly in eud view and partly in section, of a dynamo-
electric machine, or electro-motor, having this part of the invention applied
thereto;
Figure 2 is a view of one of the outer sides of the magnet with the surrounding
coils and including the pole-piece on the same side of the machine or motor, and
shews also a short length of the bed ; and
Figure 3 is a detached view of the upper portion of one of the magnet limbs and
pole-pieces, shewing the upper or outer portion of the pole-piece turned back.
In Figure 1 the upper portion of the pedestal for supporting one end of the
armature spindle is shewn as broken away, to expose parts beyond; and the
armature is indicated merely by a circle.
The upper or outer portion A. of each pole-piece is hinged at a to the lower or
inner portion B thereof, so that it may be turned back into the position shewn by
Figure 3. The lips (one of which 6 is shewn in section by Figure 1), which
usually project inwards from the pole-pieces around portions of the lower side of
the armature C, are formed separate from the pole-pieces and are carried by the
ferrule caps c which are fixed by means of bolts d to the pole-pieces. Each lip b
is, preferably, formed in one piece of metal with the corresponding cap c. When
the portions A of the pole-pieces are turned back, as described, a considerable
surface of the armature is exposed, and if desired the armature may be lifted up
between the turned-back parts of the pole-pieces clear of the machine; the ferrule
caps c, and lips b which they carry, may be drawn up over the pole-pieces and
removed from the machine, and the ferrules D carrying the coils may be also
drawn up over the pole-pieces and removed. The joint or division line e, at the
inner face of each pole-piece, between the outer or hinged portion A and the inner
or permanently fixed portion B thereof, may be as far upwards or outwards from
the transverse axis ff of the armature as will allow of the arinature being readily
drawn up from between the portions B of the pole-pieces when the portions A have
been turned back; and thus considerably more than half the total lines of force
passing from a pole-piece to the armature will pass exclusively through the portion B
thereof. In order to leave as much metal as possible in each inner portion B of
a pole-piece which is above or outwards from the transverse axis of the armature,
and to increase the area of the joint or bearing between the outer and inner
portions of each pole-piece so as to reduce to a minimum the magnetic resistance of
the joint or plane of division, and to lighten the hinged or outer portion of each
pole-piece, the joint or plane of division g is formed to slant upwards from the
inner face of each pole-piece, that is to say, from the level of the line e which
indicates the inner end of such joint or division. It is preferred to construct the
hinged joints of the pole-pieces with projections h from the hinged portions A,
which fit within corresponding recesses formed in the portions B, so as to leave no
projections from the latter portions, whereby the machining of such portions is
facilitated. Each hinge pin may be formed in two lengths a a, of which each

page_text: passes through a projection of the hinged portion A of a pole-piece and also some
distance into the part p of the inner portion B of such pole-piece which is
between the projections h h of the outer portion A thereof. Each length a of the
pin may be secured from moving end ways by means of a pin q having its head or
outer end flush with the surface of the projection h. Each hinge pin may, however,
if desired, be formed in one length so as to pass right through the part p of the
portion B of a pole-piece as well as through the projections of the outer portion
thereof. Any convenient form of hinge may, however, be adopted.
The shoulder of each hinged portion A of a pole-piece is formed to slant off
from the hinged joint to the top, as shewn, when in its normal position, so that
when such portion is turned back, as shewn by Figure 3, sufficiently for the
ferrule D to clear the inner side thereof, the outer apper corner will not overhang
or project from the plane of the outer side of the magnet.
Each hinged portion A of a pole-piece is firmly held down, when closed down on
to the fixed portion B thereof, by means of a bolt (or it may be bolts) k which
passes through a hole formed therefore in the hinged portion and is screwed into
the fixed portion; and the heads of the bolts may be formed with loops or eyes
for use in lifting the machine. It is preferred to form each bolt k with a portion m
of enlarged diameter immediately under the head, and with a similar portion n at
the part thereof which passes through the plane of division between the parts
A and B of a pole-piece, for convenience in fitting the bolts.
The hole for each
bolt is, of course, of the diameter of the enlarged portions thereof, except for a
portion of reduced diameter at the lower end into which the bolt is screwed.
Prior to the present invention, portions of the pole-pieces of two-pole single-
limb dynamo-electric machines and electro-motors have been made removable for
the purpose of facilitating the cleaning and removal of the armature, and the
removal of the ferrules carrying the magnet coils. These removable pieces have
been formed with slanted outer sides to fit between correspondingly-shaped inner
sides of the upper or outer portions of the permanently fixed parts of the pole-
pieces. The fitting truly together of inclined surfaces is, however, an expensive
and difficult operation.
Now, according to the second part of this invention, the removable pieces, aforesaid,
are formed with their outer sides struck from a common centre, so that they may be
turned true in a lathe, and the faces of the permanently fixed portions of the pole-
pieces against which the turned faces of the removable pieces bear are corre-
spondingly shaped so that they may be readily formed true by boring.
The second part of this invention is illustrated by Figure 4 of the drawings
herewith, which is a view corresponding to the upper portion of Figure 1. In this
case, however, each pole-piece consists of a portion B, which is permanently fixed,
and of a removable portion A'. The two removable portions A' are fixed together
by a grid E, or other distance-piece, and their faces g', which bear against
corresponding faces of the portions B' of the pole-pieces, are then together turned
up in a lathe so that they have a conimon centre. The corresponding faces of the
portions B are bored out when such portions are fixed in their proper relation to
one another, and thus a true fit is ensured. This method of fitting the parts
together is cheaper and simpler than that previously adopted.
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 a two-pole dynamo-electric machine or electro-motor, the pole-pieces each
formed with an upper or outer portion connected with the lower or inner portion
thereof in a manner which admits of its being turned back in relation thereto,
substantially as described.
2. A two-pole dynamo-electric machine, or electro-motor, having upper or outer
portions of the pole-pieces hinged to the lower or inner portions thereof, substantially
as described, for the purposes, or either of them, set forth.

page_text: 3. A two-pole dynamo-electric machine, or electro-motor, having upper or outer
portions A. of its pole-pieces hinged to lower or inner portions B thereof, and the
joints or planes of division between the portions A and B made to incline in an
upward or outward direction from the inner ends thereof which are preferably above
or outwards from the transverse axis ff of the armature, substantially as described
and shewn by the drawings herewith.
4. In a two-pole dynamo-electric machine in which a portion of each pole-piece
is removable from the other portion thereof, such removable portions formed with
the faces which bear against the corresponding faces of the other portions turned
truly with a common centre, and the faces against which they bear bored truly to
receive the turned faces, substantially as described and shewn by Figure 4 of the
drawings herewith.
Dated thin 7th dox of December 1804
STEPHEN WATKINS,
Wolverhampton, Agent for the Applicants.
STEPHEN WATKINS,
Wolverhampton, Agent for the Applicants.